Q; What kinds of things are you saving your money for?

A: I usually save money for playing with friends. =>  I usually save up so I can play with friends.

 => Corrected: The sentence is corrected grammatically.​​

-이번 토요일.거기서 6일동안 머물거야.

This Saturday. I'll stay there for 6 days.  (Correct)

-나한테 편지 써줄거지?

Will you send letters to me? => Can you write me a letter? => Corrected: The sentence is corrected grammatically.

-물론이지. 너한테 이메일 써줄게.

Of course. I'll send you email. => Sure. I'll send you an e-mail. => Corrected: The sentence is corrected grammatically.​