The conditional 2 is used for events less probable and for unreal events. 

• FORM: If + past simple or continuous + would, could, might + infinitive
• Note: The correct form for the verb to be in the if-clause is were (e.g. If I were you, I'd complain.), but was is also possible and is often heard in conversation.
Note 2: When there is a modal verb such as can it will change into be able to, and must will change into have to e.g.:-
• If we played very well, we would be able to participate in the contest.
• If they wanted to change the color of the house, they would have to paint it white first.