These are NOT used with people/living things. We will learn those soon.

♡To/At = 에

◆Using 에 as TO,

도서관에 전화 했어요.

I called (TO) the library.

회장님에 연락 했어요.

I contacted (TO) the company CEO.

If I were to say, 도서관 전화 했어요, it would be "The library called" and the same goes with 회장님 연락했어요. And the sentence would sound wrong.

◆Using 에 as AT,

저는 집에 있어요.

I am AT my home.

거기 어디에 있어요?

Where is that (AT)?

♡From/At = 에서

◆Using 에서 as FROM,

저 태국에서 왔어요.

I am from Thailand.

학교에서 언제 돌아왔어요?

When did you came back from school?

◆Using 에서 as AT,

집에서 먹고 있어요.

I am eating from(at) home.

학교에서 봤어요

I saw it at school.

If I plainly say 학교 봤어요 or 저 태국 왔어요, it would mean "school saw" or "I came Thailand" which sounds wrong.

That's it for today, 안녕♡