Unreal present conditional sentence

Unreal present conditional sentence
structural : If clause , Main clause
                  If clause : If + S + V-ed (simple past)
                  Main clause : S + would/could/should (not) + V (infinitive)
        If + S + V-ed , S + would/could/should (not) + V (infinitive)
EX : If i were you , i wouldn't aks him for advice
If clause have a verb in past simple
Noticed The verb " to be " is verb-form " were " use all subject 
Translate : Nếu tôi là bạn thì tôi sẽ không xin anh ta lời khuyên

EX : If he didn't killed person , he wouldn't go to prison (jail)
         Chinh wouldn't go bankrupt if he sold his land in  urban
         If I didn't left Toyota , I wouldn't see the world to be really very large