Wish & IF

 
1- Expressing wishes about the present and future:

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 hadn’t 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.

2- Expressing wishes 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 understand. (?)   
 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.


3- Contrary-to-fact in the present/Future:

If is used to talk about situation that are contrary to 
fact, situation that are the opposite of the true situation.

True situation: She doesn’t have time.
Making a wish: She wishes she had 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: We aren’t ready yet.
Making a wish: We wish we were ready.

Contrary-to-fact situations: If we were ready, 
we could/would go right now.

 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- 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 didn’t have time.
Making a wish: She wishes she had 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.
Making a wish: We wish we had been ready.
Contrary-to-fact situations: If we had been ready, 
we could/would have gone.


5- Summary:

 Situation: 
   If-clause  result clause
 In the present/Future: 
 True:   simple present will/can + simple form 
 Contrary-to-fact:  simple past  would/could + simple form
 In the past: 
 Contrary-to-fact:  past perfect   would have + past participle
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