Auxiliaries
Would - Should + Could - Might

Exercise 1 Choose correct forms: I would go, I would have gone.

Exercise 2 Complete sentences: He would come, We might have said...

Exercise 3 Complete questions: Could you do? Would they have tried?

Exercise 4 Correct mistakes: I would have done it next time. - I ___ do it next time.

Exercise 5 Match sentences: He might be here. He might have been here. - He wasn't. He isn't.

Exercise 6 Complete the dialogue: When I saw her with him, I went away. - Pity. You ___ (should | stay).

Exercise 7 Complete sentences with should, could and might.

Exercise 8 Questions and negative: Would you tell her? - No, I wouldn't tell her.

Exercise 9 Complete sentences with should have, could have, might have.

Exercise 10 Questions: Would you have arrived?

Exercise 11 Negative forms: I wouldn't have taken, He might not have left...

PDF exercises with answers:

Second conditional exercises PDF I would take my umbrella if it rained.

Third conditional exercises PDF I would have taken my umbrella if it had rained.

Mixed conditionals exercises PDF Printable tests to download for free.

Printable grammar rules:

• PDF rules printable grammar rules with examples to download for free.

There are two basic types of the conditional tense in English - the present conditional and past conditional.

Statement: I would be
Negative: He would not be
Question: Would you say?
Neg. question: Would she not practise?
Short forms: I'd do, He wouldn't ask, Wouldn't we go?
See also how to make the conditional tense in the Passive Voice.

Use

We use the present conditional tense in English (I would be, he would do etc.) to speculate about present or future situations that could theoretically happen. This form is used when the action is either impossible or when we do not think that the action will happen.
Examples: He would be here. (But he can't. It is not possible.) I would travel by plane. (If I wanted to go on holiday. But I do not want to go.)

In the first person singular and plural should instead of would is also possible. But it is not very common in modern English.
I should | would be really glad. (If you could help me). We should | would send the fax. (But we do not know how to do it).

Should, however, can also express a recommendation or advice. In this respect, it is similar to ought to.
I should study tonight. I ought to study tonight. (Or I will fail the exam tomorrow.)
He should drive carefully. He ought to drive carefully. (Or he will crash one day.)
You should speak loudly. You ought to speak loudly. (I can't hear you.)

Could and might are the conditional tense of modal verbs can and may. They are used to speculate about the present or future. Could indicates theoretical possibility, might indicates possibility + uncertainty.
She could come with us tomorrow. (It is possible. She will be free.)
She might come with us tomorrow. (We hope that it is possible, but we are not sure.)

Could is also the past form of can and expresses possibility, ability or permission in the past.
Possibility: She could travel in our car. (It was possible because we had a free seat for her.)
Ability: She could play again in the last match. (She was able to play because she was not ill anymore.)
Permission: She could come with us last weekend. (Her father allowed her to go.)

Statement: I would have been
Negative: He would not have been
Question: Would you have practised?
Neg. question: Would she not have written?
Short forms: I'd have been, He wouldn't have given, Wouldn't we have written?

We make the past conditional tense with would and the perfect infinitive (have + past participle).
In the first person singular and plural should instead of would is also possible. But it is not very common in modern English.

Use

We use the past conditional tense (I would have been | He would have done etc.) to speculate about the past situations which were theoretically possible, but did not happen in fact.
Examples: I would have done it. (But I didn't do it). I would have told her. (But she didn't want to listen.) She wouldn't have married me. (Because she didn't like me.)

Compare:

She would lend me some money now. (She is willing to lend me the money. I will ask her.)
She would have lent me some money last year. (She was willing to lend me the money, but I didn't ask her.)
Similarly: I would do it. Will you help me? x I would have done it. But you didn't help me.

Should, could and might are used in the same way.
You should finish it soon. x You should have finished it. Why did you give up?
We might have dinner. I am hungry. x We might have had dinner. But we didn't eat anything.
They could fly tomorrow. x They could have flown last week. But they stayed at home.

Should + have + past participle (should have finished) is used to express regrets or recommendations concerning the past.
He shouldn't have refused it. It was a good offer. (It is a pity that he refused it.)

Might (might have had) and could (could have flown) are used to speculate about the past. We say that something was possible, but we know that it did not happen.
He might | could have died. But they rescued him.
He might | could have won. But he didn't buy a lottery ticket.

Compare

In English we can also speculate with may. In this case we do not know if the action really happened or not.
He may have died. (It is possible that he died. But maybe he is still alive.)
He may have won. (It is possible that he won. But maybe he lost.)