1-
a) I would by a car if i knew how to drive.
b) We would go to the beach if we didn't have so much work to do.
c) If we met her, we would give her your message.
d) If we left now, we would arrive there on time.
2-
a)If he calls, I will speak with him.
b)If you study hard, you will pass your examination.
c)I will give it to you if I find your money.
d)We will have lunch to get her if you arrive on time.
3-
I would study today if I had a test tomorrow
If the police comes, they will run away
What would you do if I gave you 500 dollars?
You would have found the book if you had looked for it
She will punish Tom if he breaks the vase
If they were tired they would rest
If he drove more carefully he would have fewer accidents
4-
Simple conditional:
Nós usamos o Simple Conditional para formar sentenças no futuro do pretérito. 
Present Perfect:
Usado para ações do passado que aconteceram em tempo indeterminado,algo que acabou de acontecer e ações que se iniciaram no passado e continuam até hoje.
Conditional sentences:
Sentenças que expressam uma condição.
5-
Present Perfect é usado para indicar ações do passado que ocorreram em tempo indeterminado, ações que começaram no passado e continuam até hoje e ações que acabaram de acontecer, já as Conditional sentences são usadas para expressar condições.

Espero ter ajudado :)