Что делать ? Что сделать ??????

[Nada A]

Hello everybody

I've found these phrases in a Russian "учебник"

1. Вечером я буду готовить домашнее задание. Когда я приготовлю домашнее задание, я позвоню тебе.

2. Вечером я буду писать письма домой. Когда я напишу письма я буду учить уроки.

I want to understand why we have used a pervective verb in the first phrase and an imperfective verb in the second. I mean would it be wrong or will there be a difference in meaning if we said:

1. Вечером я буду готовить домашнее задание. Когда я приготовлю домашнее задание, я буду звонить тебе.

2. Вечером я буду писать письма домой. Когда я напишу письма я выучу уроки.

[CoffeeCup]

Когда я приготовлю домашнее задание, я позвоню тебе.

This sentence means that "I'll reach you by the phone" or "I'll have a talk with you by the phone".

Когда я приготовлю домашнее задание, я буду звонить тебе.

This one means that "I'll dial your phone number [maybe over and over again until you pick up the phone]".

Когда я напишу письма я буду учить уроки.

"I'll spent some time in doing my home tasks".

Когда я напишу письма я выучу уроки.

"I'll perform all my home tasks completely."

[John_Douglas]

zvonit' means "try to call" - so you dial the number but you may or may not get through. But when speaking in the future you usually assume that you will get through, so you use pozvonit' - "to call (successfully)".

it's sort of the same with uchit'/vyuchit' - uchit' means to study, vyuchit' means to learn, which is a long process, so it wouldn't often be used in the future perfect tense.

[Kudesnik]

zvonit' means "try to call" - so you dial the number but you may or may not get through. But when speaking in the future you usually assume that you will get through, so you use pozvonit' - "to call (successfully)".

This is quite correct, I just would say that "budu zvonit'" means "I will be calling during some time (or for several times). "Pozvonyu" means "I will make a call".

it's sort of the same with uchit'/vyuchit' - uchit' means to study, vyuchit' means to learn, which is a long process, so it wouldn't often be used in the future perfect tense.

This is not exactly true. "Uchit'" means either to study or to learn for some [undefined] time, as a long or continuos process. "Vyuchit'" means to get something learnt, to gain the knowledge of something, to complete the lesson, to make the homework done, etc. This isn't about a process, this is about the result.

[Nada A]

Thanks for all of you. Your answers were really helpful for me.