CONDITIONAL SENTENCES WITH 'IF'

There are three types of Conditional Clauses

Type-I
Likely Conditional Clause (Probability) contain a condition
that may or may not be fulfilled.
Eg: If you call me, I shall come to you.
If I have money, I will buy a car.
In type I Conditional Clause, the verb in the 'If Clause' is in present tense.

Type-I
'If' Clause
Present Tense Verb
Main Clause
will/shall/can/may + Present tense verb

Type-II
Unlikely Conditional Clause (Improbability) contains a condition that is improbable, the condition stated is not likely to be fulfilled.
Eg: If you called me, I would come to you
If I had money, I would buy a car
Type-II
'If' Clause
Past Tense Verb
Main Clause
would/ should /could/ might + Present Tense Verb

Type-III
Imaginary Conditional Clause / Unfulfilled conditions in the past.
Contains a condition that was not fulfilled in the past.
Eg: If you had called me, I would have come to you.
If I had had money; I would have bought a car
Type-III
'If' Clause
had + Past Participle of Verb
Main Clause
would / should / could/ might + have + Past Participle of verb

More examples:
Type-I: If you drop this glass, it will break.
Type-II: If you dropped this glass, it would break.
Type-III: If you had dropped this glass, it would have broken.
Type-I: If you wait, I can fetch you the file.
Type-II: If you waited, I could fetch you the file.
Type-III: If you had waited, I could have fetch you the file.
Type-I: If you like this one, I will bring you another.
Type-II: If you liked this one, I would bring you another.
Type-III: If you had liked this one, I would have brought you another.