CBSE Class 5 English Tense Worksheet

Introduction

Definition: Tense is the form of a verb, which shows the time of action and its degree of completeness. Tense gives us the knowledge of the time when an action is taking place.

Illustrative Example

• Delhi attracts a large number of migrants.
  (Present Tense)
• I thought the best way is to put an end to any controversy.
  (Past Tense)
• Mr Ayush will pass the buck for the failures of his own.
  (Future Tense)

Tense is divided into three categories. They are the following:

• (i) Present Tense
• (ii) Past Tense
• (iii) Future Tense

Present Tense expresses actions in the present time; Past Tense expresses actions in the past time; and Future Tense expresses actions in the future time.

Present Tense

It expresses an action or event that takes place at present. Present Tense is divided into four categories. They are the following:

• (i) Simple Present or Present Indefinite
• (ii) Present Continuous or Present Progressive
• (iii) Present Perfect
• (iv) Present Perfect Continuous

Simple Present or Present Indefinite

This tense ('s used t-o express the habitual action which is truths, planned activities, quotations and to put questions. This tense shows an action done in a general way in the present time.

Illustrative Example

• Smith speaks English fluently.
• Jackson recognizes me very well.
• They know well about this matter.

In the above given sentences, the verbs 'speaks', 'recognizes' and 'know' show an action done in a general way in present time. They do not say whether the action is complete or incomplete. These verbs are in Present Indefinite Tense.

Points to keep in mind:

• Present Indefinite Tense is used to show a habitual action.
  Example: Michael goes to college every day.
• Present Indefinite Tense is used to express a universal truth.
  Example: The earth moves round the sun.
• Positive sentences do not use do or does.
  You make a point.
• For the 3rd person singular (he, she, it or the name of any person), add s/es to the main verb
  My mother encourages me to take part in games.

Present Continuous Tense

The Present Continuous Tense is used to express an action or event that is taking place. This tense shows an action which is going on (or continuing) at the time of speaking.

• Vandana is taking yoga classes right now.
• India is developing day by day.
• The world is criticizing the terrorism.

In the above given sentences, the verbs 'is taking', 'is developing' and' is criticizing' show an action that is going on or continuing at the time of speaking (in present time). Here the action is incomplete. These verbs are in Present Continuous Tense.

Points to keep in mind:

• Present Continuous Tense is used to show a temporary action.
  Example: We are talking about international issues.
• Present Continuous Tense is used to show an action expected to take places in future.
  Example: My brother is going home tomorrow.
• Present Continuous Tense is used to talk about the activities happening now.
  Example: My brother is reading a book.
• Present Continuous Tense is used to talk about activities happening around now, and not necessarily this very moment.
  Example: He is working hard for his exam.

Present Perfect Tense

Present Perfect Tense is used to express the actions just completed, put questions and speak about past actions whose time is not specific. Present Perfect Tense shows an action started in the past and completed at the time of speaking (in present time).

Illustrative Example

• She has learnt the lesson.
• Smith has done this work.
• They have reviewed the situation.

In the above given sentences, the verbs 'has learnt', 'has done' and 'have reviewed' show an action started in the past and completed at the time of speaking (in present time). These verbs are in Present Perfect Tense.

Points to keep in mind:

• Present Perfect Tense is used to express an action that has just been completed.
  Example: Kunal has opened the room.
• Present Perfect Tense is used to express past actions whose time is not given.
  Example: We have painted the room.
• Present Perfect Tense is used to describe experience.
  Example: I have been to your place twice.
• Present Perfect Tense is used to talk about change that has happened over a Period of time

Present Perfect Continuous Tense

Present Perfect Continuous Tense shows an action that started at some time in the past and is continuing in the present time.

Illustrative Example

• Michael has been reading a book for two hours.
• Maickel has been sleeping since 2 PM.
• They have been working since Monday.

In the above given sentences, the verbs 'has been reading', 'has been sleeping 'and 'have been working' show an action started at some time in the past and continuing in the present time. These verbs are in Present Perfect Continuous

Tense.

Points to keep in mind:

• In Present Perfect Continuous Tense 'for' is used to suggest period of time and 'since' to show point of time.
• Present Perfect Continuous Tense is used to show the continuity of an action which began in the past and still going on.
  Example: Peasants have been ploughing the field for five hours.
  We have been discussing this matter since 27 July.

Past Tense

When a verb indicates a completed action. It is known as Past Tense.

Illustrative Example

• Michael played cricket.
• Michael was playing cricket.
• Michael had played cricket.
• Michael had been playing cricket.

In the above given sentences, the verbs 'played', 'was playing', 'had played' and 'had been playing' show an action of past time. These verbs are said to be in the Past Tense.

Past Tense shows an action done in the past time.

Past Indefinite Tense

Past Indefinite Tense is used to express past habits, completed actions and put questions. It also shows an action done in general way in the past time.

Illustrative Example

• Eight defence personnel, including three crew members, were injured when an IAF helicopter crashed.
• The Mi-26 chopper carrying defence personnel took off from the technical Airport at Satwari
• The defense lawyer argued that the judgment violated the fundamental principles.

In the above given sentences, the verbs 'were injured', 'took off' and 'argued' show an action completed in the past time. These verbs are in Past Indefinite Tense.

Points to keep in mind

• Past Indefinite Tense is used to show an action completed in the past.
  Example: Maria left the town before the scheduled departure.
• Past Indefinite Tense is used to show a habitual action in the past.
  Example: I used to play chess with my friends during leisure time.

Past Continuous Tense

The Past Continuous Tense is used to express the continuity of some past actions and to put questions. This tense shows an action going on at some time in the past and not completed.

Illustrative Example

• Prakash and his friends were celebrating their victory with great pomp and show.
• Rita was watching the video with great concentration.
• They were discussing about this matter.

In the above given sentences, the verbs 'was celebrating', 'was watching' and 'were discussing' show an action going on at some time in the past. Here the action is incomplete. The time of action may or may not be indicated. These verbs are in Past Continuous Tense.

Points to keep in mind

• Past Continuous Tense is used to show an action started and continued in the past time.
  Example: She was watching the television when I came.
• Past Continuous Tense is used to show a persistent habit in the past.
  Example: He was playing cricket.

Past Perfect Tense

The Past Perfect Tense is used to express two earlier actions, completion of past actions and to put questions. It shows an action which had been completed before another action took place.

Illustrative Example

• Vinoy had taken his meal before I arrived.
• Rajesh had gone to college before I reached.
• They had completed their job before you came.

In the above given sentences, the verbs 'had taken', 'had gone' and 'had completed' show that the action had been completed before another action took place. Here the earlier action takes Past Perfect Tense. These verbs are in Past Perfect Tense.

Points to keep in mind

• Past Perfect Tense is used to show an action completed before another action took place.
  Example: The college had closed before the professor came.
• Past Perfect Tense is used to describe an action completed before a certain moment in the past.
  Example: Deepika met Prakash in Mumbai in 2010. She had last seen him five years ago.

Past Perfect Continuous Tense

Past Perfect Continuous Tense shows an action starting before a certain point in the past and continuing up to that time.

Illustrative Example

• They had been talking for over an hour before Tony arrived.
• Michael had been working at that company for three years when it went out of business.
• James had been teaching in the university for more than a year before he left for India.

In the above given sentences, the verbs 'had been talking', 'had been working' and 'had been teaching' show an action that began before a certain point or period in the past and continuing up to that time. These verbs are in Past Perfect Continuous Tense.

Points to keep in mind

• Past Perfect Continuous Tense is used to show that the action was continuous and still going on at a point or period of time in the past.
  Example: Raj had already been teaching in this college when he applied for another job.

Future Tense

In Future Tense, a verb indicates that an action will take place in future.

Illustrative Example

• Robert will go to London tomorrow.
• Robert will be going to London tomorrow.
• Robert will have gone to London tomorrow.
• Robert will have been going to London tomorrow.

In the above given sentences, the verbs 'will go', 'will be going', 'will have gone' and 'will have been going' show an action that will happen in future. These verbs are said to be in the Future Tense. Future Tense shows an action that will happen in future (coming) time.

Future Indefinite Tense

The Future Indefinite Tense is used to express a supposed action, determination and to put questions. This tense shows an action to be done in general way in the future time.

Illustrative Example

• A computer science professor of the University of Michigan will visit India.
• The group will say the Indian government can simply ignore their message.
• They will celebrate festival in the next month.

In the above given sentences, the verbs 'will visit', 'will say' and 'will celebrate' show an action to be done in the future time. These verbs are in Future Indefinite Tense.

Points to keep in mind

• Future Indefinite Tense is used to show a future event.
  Example: Aryan will play in the room.
• Future Indefinite Tense is used when we plan to do something at the time of speaking.
  Example: It is hot. I will drink cold water.

Future Continuous Tense

The Future Continuous Tense is used to indicate the continuity of a supposed action, possible actions or to put questions. This tense shows an action going on at some time in the future.

Illustrative Example

• James will be going to Paris tomorrow.
• Indian Prime Minister will be arriving in Washington tomorrow.
• You will be waiting for her when her plane arrives tonight.

In the above given sentences, the verbs 'will be going', 'will be arriving' and 'will be waiting' show an action going on at some time in the future. These verbs are in Future Continuous Tense.

Points to keep in mind

• Future Continuous Tense is used to show an action in progress at some time in future.
  Example: We think, she will be playing when we start.
• Future Continuous Tense is used to show some future plan.
  Example: Alberto will be visiting the Taj Mahal for a week.

Future Perfect Tense

The Future Perfect Tense is used to indicate the completion of a supposed action or an action that started earlier but still continues. This tense shows an action to be completed before another action will take place in future time.

Illustrative Example

• Anshu will have bought a bike before he gets a job.
• You will have improved your English by the time you come back from the U.S.
• They will have completed the project before the deadline.

In the above given sentences, the verbs 'will have bought', 'will have perfected' and 'will have completed' show an action which will be completed by a certain time in future. Here the earlier future action takes Future Perfect Tense and the subsequent action takes in simple present tense. These verbs are in Future perfect Tense.

Points to keep in mind

• Future Perfect Tense is used to show the completion of an action by a Certain future time.
  Example: I shall have finished my lunch by 7 a.m.

Future Perfect Continuous Tense

Future perfect Continuous Tense shows an action in progress for a period of time in the future.

Illustrative Example

• Dr. Reddy will have been teaching for 20 years next month.
• They will have been talking for over an hour by the time their boss arrives.
• Mr. Sen will have been teaching at the university for more than a year before he leaves for Asia.

In the above given sentences, the verbs 'will have been teaching', 'will have been talking' and 'will have been teaching' show an action in progress over a period of time in the future. These verbs are in Future Perfect Continuous Tense,

Points to keep in mind

• Future Perfect Continuous Tense is used to show an action which will be in progress over a period of time which will end in future time.
  Example: You will have been lying sick for a year by next month.

PRACTICE EXERCISE

Fill in the blanks with suitable forms of verbs given in the brackets.

Question. Snow ________ (fall) on the mountains. (Present Indefinite tense)
Answer: Snow falls on the mountains.

Question. She ________ (speak) the truth. (Present Continuous Tense)
Answer: She is speaking the truth.

Question. He ________ (visit) this place twice. (Present Perfect Tense)
Answer: He has visited this place twice.

Question. The boys ________ (play) cricket in the park for over an hour. (Present Perfect Continuous Tense)
Answer: The boys have been playing cricket in the park for over an hour.

Commonly Asked QUESTIONS

Fill in the blanks with suitable forms of verbs given in the brackets.

Question. Vivek ________ (take) his meal now.
(a) Has
(b) Took
(c) Is taking
(d) Had
(e) None of the options
Answer: (c) Is taking
Explanation: Vivek is taking his meal now.

Question. When I called him he ________ (get) late for his office.
(a) Is getting
(b) Was getting
(c) Has get
(d) Gets
(e) None of the options
Answer: (b) Was getting
Explanation: When I called him he was getting late for his office.

Fill in the blanks with the verbs given in the brackets.

Question. Mike __ (teach) at the university for more than a year before he left for London.
(a) Had been teaching
(b) Has been teaching
(c) Teaches
(d) Is teaching
(e) Was teaching
Answer: (a) Had been teaching
Explanation: Mike had been teaching at the university for more than a year before he left for London.

Question. Jackson ________ (work) in this company for three years.
(a) Is working
(b) Has been working
(c) Was working
(d) Has worked
(e) Had worked
Answer: (b) Has been working
Explanation: Jackson has been working in this company for three years.

Question. The whole class ________ (make) noise when the teacher arrived.
(a) Was making
(b) Is making
(c) Makes
(d) Has made
(e) Has been making
Answer: (a) Was making
Explanation: The whole class was making noise when the teacher arrived.

Question. The President Obama ________ (leave for) Russia tomorrow.
(a) Left for
(b) Will leave for
(c) Was leaving for
(d) Has been leaving for
(e) Has left for
Answer: (b) Will leave for
Explanation: The President Obama will leave for Russia tomorrow.

Question. She ________ (visit) her Japanese relatives once in 1993 before she moved in with them in 1996.
(a) Has visited
(b) Was visiting
(c) Had visited
(d) Is visiting
(e) Visits
Answer: (c) Had visited
Explanation: She had visited her Japanese relatives once in 1993 before she moved in with them in 1996.

Question. Man ________ (reach) on the Moon.
(a) Reached
(b) Has reached
(c) Is reaching
(d) Was reaching
(e) None of the options
Answer: (b) Has reached
Explanation: Man has reached on the moon.

Question. He ________ (leave) his house when the police entered his house.
(a) Is leaving
(b) Has left
(c) Had left
(d) All of the options
(e) None of the options
Answer: (c) Had left
Explanation: 'He had left his house when the police entered his house.

Question. My uncle ________ (teach) me tomorrow at this time.
(a) Teach
(b) Will have taught
(c) Teaching
(d) Was teaching
(e) Is teaching
Answer: (b) Will have taught
Explanation: My uncle will have taught me tomorrow at this time.

Question. I ________ (wait) at the station at this lesion time next week
(a) Wait
(b) Is waiting
(c) Will have waited
(d) Was waiting
(e) Has waited
Answer: (c) Will have waited
Explanation: I will have waited at the station at this time next week.

Question. Smith ________ (not learn) his lesson till yesterday.
(a) Is not learning
(b) Has not learnt
(c) Not learns
(d) Has not been learning
(e) Had not learnt
Answer: (e) Had not learnt
Explanation: Smith had not learnt his lesson till yesterday.

Tenses Gap Filling Class 5 English Worksheet

Question. They exchange merchandise rather than ……………………….. cash refunds.
a) give
b) giving
c) to give

Answer : A

Question. If you don't sue now, you …………………….. your property.
a) will never regain
b) would never regain
c) never regain

Answer : A

Question. As he grew older, his mind ………………….. further into the past.
a) regresses
b) has regressed
c) regressed

Answer : C

Question. The distraught man kept ranting until he ……………………. away.
a) led
b) has led
c) was led

Answer : C

Question. The old man ……………………. all his property to his son.
a) left
b) leave
c) was left

Answer : A

Question. Our firm …………………………. quite a lot of business in the Middle East.
a) does
b) do
c) doing

Answer : A

Question. I knew it was futile but I …………………… to him nonetheless.
a) talk
b) talked
c) have talked

Answer : B

Question. She had a knack for prophecy and ……………………… rarely wrong.
a) is
b) was
c) has been

Answer : B

Question. He has put most of his money in the bank and …………………….. on a mere pittance.
a) live
b) lived
c) lives

Answer : B

Question. If you ………………………. it properly the first time, you won't have to do it again.
a) do
b) did
c) have done

Answer : A

Question. Although she suffered many hardships, she ………………………. in her efforts to get a college education.
a) persists
b) persisted
c) has persisted

Answer : B

Question. The government refunded the overpayment I ……………………… on my taxes.
a) have made
b) make 
c) made

Answer : C
 

Choose the correct verb from those in brackets:

a. The earth _____ round the sun. (move, moves, moved)
Answer : moves

b. My friends _____ the film yesterday. (see, saw, have seen)
Answer : saw

c. It started to rain while we _____ tennis. (are playing, had played, were playing)
Answer : were playing

d. I _____ English for five years. (have been studying, study, am studying)
Answer : have been studying

e. The train _____ before we reach the station. (arrives, will have arrived, had arrived)
Answer : will have arrived

f. Don't disturb me. I _____ my work. (do, did, am doing)
Answer : am doing

g. Fortune _____ the brave. (is favouring, will favour, favours)
Answer : favours

h. I _____ the letter before you arrived. (had written, wrote, will write)
Answer : had written

i. He _____ us next week. (will have met, will have been meeting, will be meeting)
Answer : will be meeting

j. Perhaps we _____ Delhi next month. (visit, will visit, visited)
Answer : will visit
 

Complete the dialogue.

Rashid: Rahul! Your friend Manas has sent you a postcard. It’s from Kerala. It ____ (look) nice.

Rahul: I bet it does!

Rashid: He ____ (write) that it’s very hot there. There ___ (be) a lot of tourists. The hotels ____ (be) full. He ____ (say) the restaurants ____ (be) always full!

Rahul: Yes. I’m sure it is. The papers____ (say) that the temperature there is 30C.

Rashid: Then he ___ (write) that he has learnt a bit of Malayalam, and that he ____ (get on) well with the people there, especially the women!

Rashid: Look, didn’t the newspaper ____ (say) that there’s another strike in Kerala.

Rahul: Yes, it did Manas won’t mind having to stay in Kerala longer!

Answer : a. looks
b. has written
c. are
d. are
e. says
f. are
g. say
h. writes
i. gets on
j. say
 

Correct the following sentences:

i. I lived in Calcutta since 1930.
Answer : I have been living in Calcutta since 1930.

ii. She died before her husband came.
Answer : She had died before her husband came.

iii. I have written a letter to her last Monday.
Answer : I wrote a letter to her last Monday.

iv. I am reading Kalidasa for the last six days.
Answer : I have been reading Kalidasa for the last six days.

v. The new hotel has been opened last Saturday.
Answer : The new hotel opened last Saturday.

vi. He had gone to Madras last week.
Answer : He went to Madras last week

vii. The train leave the station before I reached there.
Answer : The train had left the station before I reached there.

viii. I wish my men had been coming quickly and find us.
Answer : I wish my men came quickly and found us.

ix. At the moment the baby sleep in the cradle.
Answer : At the moment the baby is sleeping in the cradle.

x. He goes out for ten minutes.
Answer : He has gone out for ten minutes.

SUBJECT : Tenses (Rewrite or Combine)

A) Change the tense of the following:

1. They often play cards.
a) When I saw them,…. When I saw them, they were playing cards……………
b) for two hours …….. They have been playing cards for two hours. ………….
c) While we were studying maths, ………………………………………………..
d) three hours ago …………………………………………………………..
e) on Saturday nights ………………………………………………………….
f) at the moment

2. John copies two cassettes everyday.
a) since 8 o’clock ………………………………………………………….
b) at present …………………………………………………………
c) next Saturday …………………………………………………………
d) already …………………………………………………………
e) yesterday …………………………………………………………

3. Kathy is writing a letter now.
a) every two weeks …………………………………………………………
b) while we were playing …………………………………………………………
c) when she is alone …………………………………………………………
d) just …………………………………………………………
e) next month …………………………………………………………
f) last week …………………………………………………………

4. He usually reads magazines.
a) for an hour …………………………………………………………
b) when I saw him …………………………………………………………
c) every morning …………………………………………………………
d) now …………………………………………………………
e) yet …………………………………………………………

5. The children are doing their homework.
a) yet …………………………………………………………
b) just …………………………………………………………
c) every evening …………………………………………………………
d) when she came

B) Read the passage and ask questions:

Janet Johnson is a film actress. She made several animal films. She is talking about an elephant called HEKIMA.
“I met Hekima when I went to Africa seven years ago. We were in Tanzania and we were making a film about elephants. When we arrived, we saw three young elephants. They were playing together. Hekima was small, friendly and intelligent. We called her Hekima because it means “wisdom”. Hekima was a great actress, and the film made her famous. After we finished the film we left Africa. I thought I’d never see Hekima again. But she left Africa, too. She came to a zoo in the USA. I was working in New York when I heard about that. She was happy when she saw me. She was playing happily. I think she remembered me.”

1. ___________________________________________________________________ ?
Janet went to Africa seven years ago.

2. ___________________________________________________________________ ?
Janet was making a film in Tanzania.

3. ___________________________________________________________________ ?
The elephants were playing when they arrived.

4. ___________________________________________________________________ ?
Because Hekima was an intelligent elephant.

5. ___________________________________________________________________ ?
It means “wisdom”.

6. ___________________________________________________________________ ?
Hekima was in a zoo in the USA while Janet was working in New York.

7. ___________________________________________________________________ ?
Hekima was playing when Janet went to see her.

C) Match the sentences using WHILE and PAST CONTINUOUS / PAST SIMPLE:
_______A________         ________B__________
1. I (burn) my finger.                I (drive) to work.
2. I (break) a cup.                    I (eat) a nut.
3. My car (break down).            I (cook) the dinner.
4. I (see) a shark.                     I (do) the washing up.
5. My clothes (get) dirty.           I (swim) in the sea.
6. I (break) a tooth.                  I (clean) my room.
1. ….I burnt my finger while       I was cooking the dinner. …….
2. ……………………………………………………………….
3. ……………………………………………………………….
4. ……………………………………………………………….
5. ……………………………………………………………….
6. ……………………………………………………………….

D) Use the correct form of the verbs:

1. The Bartons ……………… (go) to the mountains last weekend. While they ……………...(have) lunch, a man ……………………. (fall) down the tree. They ……………………… (take) him to the hospital in their car. They ……………………………………… (visit) him twice in the hospital since that time. The man ………………….. (be) better now and the doctors say he ………………………………….. (leave) the hospital soon. When The Bartons …………………
(visit) him yesterday, they ………………………. (take) him a bunch of flowers. The man …………………. (be) very happy and …………………………. (thank) them. Mr. Barton now says he ……………………………………. (spend) the next weekend at the seaside and he…………………………… (hope) there …………………………………. (not / be) any more accidents.

2. I …………………………. (finish) school last month and I ……………………………….. (not / have) a job yet, but fortunately I ……………………. (have) a job interview tomorrow. I usually ……………………. (get) up early so often …………………….. (sleep) at around half past ten. I …………………. (be) a little excited last night and because of this I ……………….. ………………………….. (want / watch) TV before I ……………………… (go) to bed. There ………………….. (be) a film about birds on TV and while I ……………………………… (sit) on the sofa, I …………………….. (fall) asleep. …………….. you …………………. (have) a terrible dream? Well, I …………………. (have) one last night. In my dream I ……………. (be) a parrot and my apartment flat …………….. (be) on the tenth floor of a big building. A big cat ……………………………………….. (want / catch) me so I ………………………………….. (begin / fly). I …………………….. (have) nowhere …………………… (go) because the door ………………… (be) locked. Suddenly the cat ………………………… (attack) me. It nearly …………………………. (kill) me. While I ……………………………. (shout) in pain,a voice……………………(say), “ ………………… you ………………….. (see) my books? I can’t find them.” When I ……………………… (open) my eyes, I ……………………. (feel) very happy ………………. (see) my sister. Of course she …………………………………. (not / understand) the reason but I ………………………… (give) her a big kiss.

E) REWRITE or COMBINE the following:

1. It rained this morning. The children played in the garden. (while)
2. What did you do? The doorbell rang. (when)
3. I walked along Main Street. I realized a man behind me. (when)
4. I started to play football when I was five. (since)
5. The windows are dirty. I last cleaned them last month. (since)
6. He last shaved a week ago. (for)
7. Maybe the train leaves at six. I don’t catch it. (If)
8. We slept last night. The robber stole all the jewellery. (as)
9. Tom prefers learning French to learning Japanese. (would rather)
10. Angela looks after many children. It keeps her busy. (Gerund)
11. He went to London. He wanted to work there. (to)
12. They had a picnic. The forest caught fire. (as)
13. No sound could be heard. The walls were very thick. (because)
14. My bed is terribly hard. I can’t sleep well. (so ……… that)
15. The shopkeeper doesn’t let the children put their fingers on the glass while they are looking at the sweets. (be allowed to)
16. My mother would rather cook than iron. (prefer)
17. We bought this house in 1990. (since)
18. He may come late. He will call us. (If)
19. Paris isn’t as crowded as New York. (comparison)
20. My father would rather read newspaper than watch TV. (prefer)

F) Look at the chart and make sentences as in the examples:

                              YESTERDAY            TODAY                 TOMORROW
people / travel        on horseback         by plane                    in spaceships
children / play        hide-and-seak        computer games       with robots
man / explore        the poles                solar system              galaxies
we / live in            villages                    modern cities             undersea cities
wives / use            handmade tools     electric appliances     intelligent robots
vehicles / run by    horses                    petrol                         water / electricity

1. People traveled on horseback yesterday.
People are traveling by plane today.
People will travel in spaceships tomorrow.