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Conditional sentences
If mice had been cats, what would they have claimed?
1. Summary of basic verb form usage in
conditional sentences:
| Situation: | If-clause | Result clause |
| In the present/future: | |
| True: | simple present | simple present
(Simple future)
Will/can + simple form |
| Contrary-to-fact: (Untrue) | simple past | would/could + simple form |
| | |
| In the past: | | |
| Contrary-to-fact:(Untrue) | past perfect | would have + past participle |
2. True in the present or future:
The simple present is used in the result clause to express
a habitual activity or situation:
If he doesn’t sleep, he always feels tired during the day.
Either the simple present or the simple future is used in the
result clause to express an established, predictable fact.
Water freezes (will freezes) if the temperature goes below 0degree.
The simple future is used in the result clause when the
sentence concerns a particular activity of situation in the future.
If you hear about, we will go to see him.
He will go shopping tomorrow if he has much time.
3. Untrue (Contrary-to-fact)
in the present/future:
If is used to talk about situations that are contrary to fact,
situations that are the opposite of the true situation.
True situation: She doesn’t have time.
Contrary-to-fact situations: If she had time, she could/would stay with us.
= She could/would stay with us if she had time.
Conditional sentence = If-clause, result clause = Result clause If clause
Would: Wants to = intended or desired
Could: Expressing a possibility, possible options = would be able to.
True situation: She isn’t he.
Contrary-to-fact situations: If she were he, she could/would go right now.
Were is used for both plural and singular subjects. Was (with he, she,
and used, but it’s informal)
Contrary-to-fact sentences with an if-clause and a result clause are called
conditional sentences. Special verb forms are used:
The simple past tense is used to discuss a present or future
situation in an if-clause.
Would or could + a simple form of the verb is used in the result clause.
True situation:
She doesn’t have time.
True situation:
If She has time, She will/Can stay with us.
We can use the simple present in a if-clause of the conditional
clause and will/can + a simple form of the verb in a result clause:
Perhaps she doesn’t have time. If that is true, she will stay with us.
Contrary-to-fact situations: If she had time, she could/would stay with us.
In reality, in true, in fact she doesn’t have time. But in the contrary, if
the opposite were true she would/could stay.
4. Untrue (Contrary-to-fact) in the past:
The past perfect tense is used to discuss a past situation in an if-clause.
Would have or could + have + past participle is used in the result clause.
True situation:
She hadn't had time.
Contrary-to-fact situations:
If she had had time, she could/would have written to us a letter.
True situation:
We weren’t ready yesterday.
Contrary-to-fact situations:
If we had been ready, we could/would have gone.
In speech, the auxiliary verbs are almost always contracted.
You had = you’d
I would have = I would’ve = I’d’ve
5. Using progressive verb forms:
True:
He is sleeping right now, so she will not leave the house.
Conditional:
If he were not sleeping right now, she would leave the house.
True:
He is not sleeping. She is not reading.
Conditional:
If he were sleeping, she would be reading.
True:
He was sleeping last night, so she did not go outside.
Conditional:
If he had not been sleeping last night, she
would have gone outside.
True:
He was not sleeping yesterday; she was not reading the book.
Conditional:
If he had been sleeping last night, she would have been reading a book.
6. Using Mixed times in Conditional sentences:
True:
He did not sleep last night, so he is tired now.
Conditional:
If he had slept last night, he would not be tired now.
(Past) (Present)
True:
He is not able to drive a car. He did not arrive on time yesterday.
Conditional:
If he were able to drive a car, he would have arrived on time.
(Present) (Past)
Frequently, the time in the if clause and the time in the result
clause are different: one clause may be in the present and the
other in the past.
7. Using could, might, and should
If he were a cat, he could eat mice.
Could= would be able
If he could run quickly, he would be the first.
Could = were able to
If she had had the answer, she could have answered the question.
Could have = would have been able to
If he doesn’t have a car, he might walk.
He might = maybe he will
If she were at home, she might avoid the trouble.
She might = maybe she would
If he had joined her, he might have been good friend.
He might have been = maybe he would have been
If he should come, tell him she will be back around four.
If he should come is more certainly than if he comes.
If there should be another hurricane, the city would be in trouble.
If there should be indicates more uncertainty or doubt than if
there were.
Omitting if:
Were he she, he wouldn’t do that.
With were, had, and should, sometimes if is omitted and
the subject and verb are inverted.
Had she seen that, she would have changed her mind.
Should anybody come, please let me know.
Were he she = if he were she
Had she seen = if she had seen
Should anybody come = if anybody should come
had he left the class ten minutes ago, he will have been at home.
Implied conditions:
She would have come, but she had to do.
Implied condition: If she hadn’t had to do.
He never would have come without the call.
Implied condition: If he hadn’t received the call.
Often the if clause is implied, not stated.
He leaves; otherwise, he would have seen her.
Conditional verbs are frequently used following otherwise.
The implied if clause is: if he hadn’t left.
8. Expressing wishes:
About the present:
The true situation: Expressing a wish about that situation:
(Present) (Simple past)
She doesn’t see him. She wishes (that) she saw him.
They are not present. They wish (that) they were present.
He can understand. He wishes he couldn’t understand.
I don’t have time. I wish I had time.
I have been worried. I wish I had been worried.
He has to wait. He wishes he didn’t have to wait.
She is absent. She wishes she weren’t absent.
We make wishes when we want the reality to be different,
to be exactly the opposite (or contrary) of the situation.
A noun clause followed WISH. The verbs used in the noun
clause are special.
When we express a wish in the present, we use the past verb
form (simple past).
Note WERE is used for all subject (I, you, she/he/it we, they).
I don’t have time. I wish I had time.
I don’t have time, but I wish I did.
She is absent. She wishes she weren’t absent.
She is absent, but She wishes she weren’t.
He can understand. He wishes he couldn’t understand.
He can understand, but He wishes he couldn’t.
When we use a comma and but (, but), we use the appropriate auxiliary.
About the future:
The true situation: Expressing a wish about that situation:
(Future) (Simple past)
He will not come. She wishes (that) he would come
She isn’t going to come. He wishes she were coming.
He can drive. She wishes he couldn’t drive.
About the past:
When we express a wish in the past, we use the past perfect.
The true situation: Expressing a wish about that situation:
(Simple past) (Past perfect)
She didn’t see him. She wishes (that) she had seen him.
They were not present. They wish (that) they hadn’t been present.
He could understand. He wishes he couldn’t have understood.
I didn’t have time. I wish I had had time.
I had not time. I wish I hadn’t had time.
He had to wait. He wishes he hadn’t had to wait.
She was absent. She wishes she hadn’t been absent.
When we use a comma and but (, but), we use the appropriate auxiliary.
I didn’t have time. I wish I had had time.
I didn’t have time, but I wish I had.
She was absent. She wishes she hadn’t been absent.
She was absent, but She wishes she hadn’t.
9. Using would to make wishes about the future:
If he comes, she wishes he would stay home.
(She wants him to stay home)
She expects receive a mail. She wishes the mail would arrive.
(She wants the mail to arrive)
Would is usually used to indicate that the speaker wants
something to happen in the future. The wish may or may
not come true (be realized).
It is going to be a good trip. She wishes he would come.
He is going to be there. She wishes he would hurry.
(She wants he to hurry)
… Wish … would … is often used to make a request.
10. Using As if and as though
He looks like a professor.
Like is followed by a noun object.
He looks as if he is going to leave.
She looks as though she is going to dance.
As if and as though are followed by a clause.
She looks like she is going to say something.
Like is followed by a clause is an informal usage.
True statement: Verb form after as if / as though
She is not a professor. She speaks as if she were a professor.
(Present) (Present + as if + negative and past form)
He didn’t stay at home. He looked as if he had stayed at home.
He has seen her. He looked as though he hadn’t seen her.
She will call him. She spoke as if she wouldn’t call him.
Usually the idea following as if / as though is untrue.
In this case, verb usage is similar to that in conditional
sentences.
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