Карл Линней. Предпосылки к созданию теории

Помогите раскрыть скобки и употребитьглагол в нужном времинию.

 1. If you (to come),we(to see) a new film.

 2.When I (to leave), I (to send) you a letter.

 3.We(not to go) to the stadium if you (to be busy) on Sunday.  

 4.When she (to buy) tickets, she (to tell) us about it.

 5.I (to help) him if he (to ask) me.