Здрасти! Помогите пожалуйста отыскать и поправить ошибки в последующих предложениях!!!! Ill

Здрасти! Помогите пожалуйста отыскать и исправить оплошности в последующих предложениях!!!!
Ill do it when I have finished to eat.
I shall bring them as soon as I has bought them.
Our parents, which are very old, live here.
I shall do it when I finished this letter.
Cars what are expensive are usually fast.
What a beautiful valleys!
This man what is my neighbour has caused the accident.
Заблаговременно спасибо!)