English Grammar Step by Step

1 a can2 b will/shall be able to3 c has been able to d be able to e can

2 a could4 b was able to beat/managed to beat/succeeded in beating c could/was able to d was able to convince/managed to convince/ succeeded in convincing e could not/was not able to

3 a could fix/would be able to fix b could have got/would have been able to get c could have played/would have been able to play d could console/would be able to console e could unscrew/would be able to unscrew

4 a may/can5 b may not/cannot/will not be allowed to c can/may d have always been allowed to e can/may

5 a Could/Can/May b Could/Can; can (or May; may) c Can/Could; cannot (or May/Might; may not) d Could/Can; can (or May/Might; may) e Could/Can/May

6 a could not/was not allowed to b was allowed c could not/was not allowed to d could/were allowed to e could only see/were only allowed to see

7 a could have played/would have been allowed to play b could/would be allowed to hunt c could/would be allowed to get d could/would be allowed to go e could have joined/would have been allowed to join/could join/would be able to join

8 a may not b cannot c cannot d may not e cannot

9 a could b could/would be able to c can/will be able to d can/may e will be allowed to/may/can f were allowed g were allowed to h Could; cannot (or May/Might; may not) i cannot/should not/ought not to j cannot/ought not to/should not k will/shall be able to l would (or "should") be able to/could m can/may n be able to o could/was able to p was able to win/managed to win/succeeded in winning q was able to see/managed to see/succeeded in seeing r are not allowed s cannot t be allowed to u could/were able to v Could/May/Can w can x Can y would be able to/could; would be able to/could z can/will be allowed to/may

10 a Who can/could it be now?; may/could/might b may/could/might c may/might/could; may/might/could d may/might/could e may/might

11 a may/might/could b may/might/could c might/could/may d may/might; may/might e Do you think (that) he'll.../Is it possible/probable/likely that he'll.../Is he likely to help us...?

12 a can b can/may c could d cannot e cannot

13 a cannot b cannot c may not/might not d may not/might not e could not

14 a could not b might/could; might/could c could not d could not e might/could

15 a could/can b could/can c could/can d could/can e Could/Can

16 a may/might/could b may/might/could c cannot d could/can; could/can e might/could f can g could/might/may h may i may/might/could j can k Could/Can; can (or May/might; may) l can m could; could; was able to get/managed to get/succeeded in getting n Could o could/might p could q are not allowed to smoke/may not/cannot r could/would be able to s could/can t can u could v could/might/may w Do you think (that) x cannot/should not/ought not to y can z have been allowed to

17 a could/might b could/might c could/might d may/might/could; may/might/could; may/might/could; may/might/could e may/might/could; may/might/could

18 a cannot/could not b cannot/could not c cannot/could not d may not/might not; cannot/could not; may not/might not e could not/cannot

19 a have to b must c have to/will have to/must d have to e has to

20 a had to b had to c will have to/must d has had to e would have to

21 a need not/do not have to/do not need to b need not/do not have to/do not need to c do not have to/do not need to d need not/do not have to/do not need to e do not have to/do not need to

22 a may/might/could b may/might c can d could/might e Can/Could; can (or May/Might; may) f may/might/could; may/might/could; may/might/could; cannot/could not g may/might h must i cannot j must k must/will have to l need not/do not have to/do not need to m could/might n must/will (or shall) have to; cannot o had to/would have to/must; could not p may/might/could; may/might/could q cannot; must/will (or shall) have to/have to r must/have to s could t can/could u need not/do not have to/do not need to v does not have to/does not need to; does not have to/does not need to w did not have to/did not need to x cannot y cannot z were able to break/managed to break/succeeded in breaking

23 a need not have awaited b need not have gone c did not have to lie/ did not need to lie d need not have come e did not have to write/did not need to write

24 a Need/Must (or Do I have/need to) b Need/Must (or Do we have/need to) c Need/Must (or Do I have/need to) d need/must (or do you have/need to) e Need/Must (or Do I have/need to)

25 a must6 b must c must d must e must

26 a must not/should not/ought not to/cannot b may not c must not/cannot/should not/ought not to d must not/should not/ought not to/cannot e must not/cannot/should not/ought not to

27 a must7 b must c must d must e must

28 a may/might b Can/Could c must d must e must not/should not/ought not to f Could g must/will have to/have to h cannot/could not; must i should not/ought not to j should/ought to/must k need not/do not have to/do not need to/should not/ought not to/must not l cannot; must m must/will have to n can/will be able to/are able to o may/might/could; can p cannot q need not; could/might/should/ought to r did not have to/did not need to s Need/Must t must not; can/could u may not/are not allowed/permitted to; must v Do you think (that) they.../Is it possible (or probable/likely) that they.../Are they likely to play... w cannot x does not have to/does not need to y had to z was able to pass/managed to pass/succeeded in passing

29 a could/might8 b could/might c could/might d could/might e could/might

30 a should not/ought not to b should not/ought not to c should/ought to d should not/ought not to e should not/ought not to

31 a ought to/should b ought not to/should not c ought to d ought not to/should not e ought to/should

32 a should b should c should/would d should e shall/should

33 a should/ought to b should/ought to c should/ought to d should/ought to e should/ought to

34 a may/might/could; cannot; may/might/could b could/can c should/ought to/must d should not/ought not to/must not e cannot/could not f must/should/ought to g could not h cannot; must i may/might j must not/cannot k will have to l should not/ought not to; could not m should/ought to/could/might n could o should/ought to p could not q should not/ought not to/must not/cannot r should s cannot/must not t should not/ought not to u Should we shack/Ought we to shack v need not pay/do not have to/do not need to; can w Need/Must x ought to y must z should not/ought not to/must not/cannot

35 a you should arrive/you arrive b any proof (should) be/any proof is/for any proof to be destroyed c should say/says d she (should) be/for her to be here e you should like/you like; you should like/you like

36 a (should) train9 b (should) read/advised my reading c (should) clear/proposed our clearing/that we cleared d (should) study/urged his studying e the meeting (should) be postponed/was postponed/demanded to postpone the meeting

37 a should need/needed b (should/might) take/took c should hail/ hails d Should e could/would/should

38 a should/ought to/must b might/could c must d cannot e must/will have to/have to; should be/are f Need/Must (or Do I have/need to); Can't/Couldn't g must/should/ought to h need not i must j should k she (should) be/for her to be/she is; could/might l (should/might) be/was m could/might/may n must; you should learn/you learn/for you to learn o should p must q will have to r must s must t cannot; must/will have to u should not/ought not to/must not; could/might/may/can; can v you should think/you think/ridiculous to think w (should/must) x must y could not z (should); should break/broke

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1  I have not used contractions in the answers given, but the following contracted forms are possible in colloquial language:
     cannot→can't
     could not→couldn't
     does not→doesn't
     do not→don't
     may not (not normally contracted)
     might not (not normally contracted)
     must not→mustn't
     need not→needn't
     ought not→oughtn't
     should not→shouldn't
     was not→wasn't
     were not→weren't
2  Is able to is possible here but not so common as can. Be able to may replace can (for present ability) in this key.
3  If we take this as a suggestion, can should be used.
4  Could is very much preferred to was/were able to for perception verbs. For this reason, I shall only use could in this key.
5  Be allowed to is far less usual than can or may. For this reason, I shall usually use can or may in this key, unless be allowed to is the only alternative.
6  Although has to is often found in American usage, I have not included it in the key.
7  Should and ought to are also possible in this section, but the advice is less strong.
8  Should and ought to are also possible in this section.
9  Verbs such as order, direct, command, urge and advise may be followed by the person addressed plus an infinitive with "to", but this implies that we are talking direct to him or her.