Using First and Second Conditioal Sentences

There are several ways of conditional sentences in English. Here you have a diagram

TYPE	MEANING	IF-CLAUSE	MAIN CLAUSE
Type 0 or REAL	General truth; you can substitute if for when	Present If you boil water	Present it evaporates
Type 1 or  POSSIBLE/ PROBABLE	Possible condition; it is likely to happen	Present If I have time if you have finished your homework	Future I’ll go to the cinema I`ll give you a present/you can play with the computer
Type 2 or UNPROBABLE	Improbable condition; it is very hypothetical that this could happen	Simple past If I could buy a new car If I had the money	Simple conditional I’d take a van I wouldn't buy a Ferrari

Let's work with some exercises:

• exercise 1     exercise 2     exercise 3     exercise 4

There is another link which is not explained in the book but it's imortant to know: UNLESS

This form is the same as if...not; for example: I won't go unless you invite me or You'll have problems unless you do it carefully. If you want to practise, you can use this exercise; click here

Although the second conditional (hypothetical) is mentioned above, we are not going to use them now but in a higher level unless you use it in this way: If I were you, I'd stay at home or If I were Peter, I wouldn't tell her the truth. 

To finish with, here you have the song When a Man Loves a Woman to see examples of what it's been explainded here; click here