will vs be going to

will	be going to
의지표현	이미 계획(예정)이 되어있는것

1. be going to 계획(예정)이 되어 있는것
   I’m going to wake up early tomorrow.
   I’m going to go to bed late tonight.
   I’m going to watch a movie this weekend.
   I’m going to hang out with my friends tonight.
   We’re going to have a drink.

2. will 의지(의사)표현
   I’ll do that. You don’t have to do that, I’ll do that.
   I’ll lend you 50 dollars.
   I’ll help you.
   I’ll ask her when I see her.

ex. My mother is sick right now and she’s at the hospital.
A: 아, 네 알고 있습니다. 이번 주말에 병문안 드릴겁니다.
Yes, I know. I‘m going to visit her this weekend.
B: 아 정말요? 어쩌죠? 너무 유감이에요. 제가 이번 주말에 병문안 드릴게요.
Oh, really? I’m sorry to hear that. I‘ll visit her this weekend.

출처:라이브 아카데미