Present Unreal Conditional.

1. Unreal conditionals have the characteristic that the dependant clause describes an imaginary, imposible condition or event, and the main clause express the imaginary or imposible result. That is waht the past tense represent. 
Example:
If we went out to dinner I would change my dress. 

2. In this grammar form, modals are used to show the unreality of the condition.
Example: 
If she were happy with him, she would open the door. 
If he had the time to do it, he may study for the test. 

3. The form "If I were you..." is used to give advices in a softly way that usign should or ought to.
Example:
If I were you, I'd ask them for help with the event.

The infformation about advices could be cheked in this link:
BBC World Service. Language Point. 

4. Grammar forms as "Would you mind if..." "Would it bother you if..." or "Would it be OK if..." are used for ask for permission. 
Example:
Would you mind if  I invited her to the dance?
Would it bother you if I drove tonight?
Would it be OK if I went to the party?