Conditionals (if-clauses) types 0,1, 2 and 3

Type 0 – Facts / truth

If + Present Simple + Present Simple

Examples:

If they heat water, it boils.

Life on Earth ends if it doesn't rain enough.

Type I – Probable situation

If + Present Simple + Future “will” + Infinitive

or

Future “will” + Infinitive + If + Present Simple 

Examples:

If I study hard, I’ll pass my exams.

I won’t go to the beach on Saturday if it rains.


Type II – Improbable situations, give advice.


If + Past Simple + Conditional “would” + Infinitive

or

Conditional “ Would” + infinitive + if + Past Simple 



Examples: 

If I were you, I would go to the dentist immediately. 
I wouldn’t speak to them ever again if I were you.

Type III – express regret to something you have done; impossible, imaginary situations.


If + Past Perfect + would + have + Past participle
or
Would + have + past participle + if + past perfect


Examples:

If I had studied harder, I wouldn’t have failed the exam.

I wouldn’t have had a car accident if I had paid attention.

Now, it is time to work!! 
1 - http://web2.uvcs.uvic.ca/elc/StudyZone/330/grammar/0cond1.htm
2 - http://web2.uvcs.uvic.ca/elc/studyzone/410/grammar/2cond1.htm
3 - http://web2.uvcs.uvic.ca/elc/studyzone/410/grammar/2cond2.htm
4 - http://web2.uvcs.uvic.ca/elc/studyzone/410/grammar/3cond1.htm
5 - http://www.englisch-hilfen.de/en/exercises/if_clauses/multiple_choice2.htm
6 - http://speakspeak.com/english-grammar-exercises/upper-intermediate/zero-first-second-third-conditionals