Little more about if condition

When you come across the "if" word in any sentence, then be careful about the following about the sentence schema:
If Clause Then Clause
Present will + Base(Main) verb
If Roger win, he will be the first person to win 5 US open successively.
Past would/ could + Base(Main)verb
If Avix failed ...... , he would go .........
Past perfect would/could + have + Participle
If Napoleon had conquered ..... he would have given a new ..........


Please be careful while writing and using "If" condition and keep above simple rules in your mind. We've a tendency to use excessive usage of would/ could but sometimes they are not at all required!

Will Vs Would

Conditional Clause and Main Clause

If I have enough money, conditional clause	I will go to Japan.     main clause
I will go to Japan, main clause	if I have enough money     conditional clause

First, Second, and Third Conditional

1. First conditional:	If I have enough money, I will go to Japan.
2. Second conditional:	If I had enough money, I would go to Japan.
3. Third conditional:	If I had had enough money, I would have gone to Japan.

 

Conditional clause	Main clause
1. If + Present Tense	will + inf / present tense / imperative
If you help me with the dishes (if + pres), I will help you with your homework. (will + inf) If the sum of the digits of a number is divisible by three, the number is divisible by three (Pres. tense) If you see Mr Fox tonight, tell him I am ill. (imperative).
2. If + Past Tense	would + inf
3. If + Past Perfect Tense	would have + past participle
We do not normally use will or would in the conditional clause, only in the main clause.

Uses of the Conditional

1. First conditional
   
   
   1. Nature: Open condition, what is said in the condition is possible.
      
   2. Time: This condition refers either to present or to future time.
      
      e.g. If he is late, we will have to go without him.
      
      If my mother knows about this, we are in serious trouble.
   
   
   
   
2. Second conditional
   
   
   1. Nature: unreal (impossible) or improbable situations.
      
   2. Time: present; the TENSE is past, but we are talking about the present, now.
      
      e.g. If I knew her name, I would tell you.
      
      If I were you, I would tell my father.
      
      Compare: If I become president, I will change the social security system. (Said by a presidential candidate)
      
      If I became president, I would change the social security system. (Said by a schoolboy: improbable)
      
      If we win this match, we are qualified for the semifinals.
      
      If I won a million pounds, I would stop teaching. (improbable)
      
   
   
   
   
3. Third conditional
   
   
   1. Nature: unreal
      
   2. Time: Past (so we are talking about a situation that was not so in the past.)
      
      e.g. If you had warned me, I would not have told your father about that party.(But you didn't, and I have).