It means hard or difficult. ✔​

It will be tough. ✔​

The question was tough for me. ✔​

The teacher told me that is tough. ✔​

Is it a tough case? ✔​

It's tough to approach for him. —> It's tough to approach for him.

=> Corrected : The sentences were corrected grammatically.​

B. Make these sentences into English.

좋아. 어디서 만날까?

Okay. Where shall we meet? —> That's good. Where can we meet?

=> This sentence is okay. This is another way of saying it. 

​

너희 집 앞에서.

In front of your house. ✔​

좋아, 3시에 보자.

That's good. Let me see at 3 o'clock. —> OK. See you at three.

=> This sentence is okay. This is another way of saying it. ​