pigonhanikka jibeseo swieoyo.

Because I’m tired, I rest at home.

Breakdown of pigonhanikka jibeseo swieoyo.

• 집: home
• ~에서: location particle
• 피곤하다: tired
• 쉬다: to rest

Questions & Answers about pigonhanikka jibeseo swieoyo.

What does -(으)니까 mean here?

It’s a connective meaning because/since. It links a reason clause to a result clause. In 피곤하니까 집에서 쉬어요, the reason is 피곤하니까 (because [someone is] tired) and the result is 집에서 쉬어요 (rest at home). The reason typically comes first in Korean.

Why is it 피곤하니까 and not 피곤해니까?

With -(으)니까, you attach it to the verb/adjective stem. The stem of 피곤하다 is 하-, so it becomes 피곤하니까.
The form 해 is the contraction of 하여 used with endings like -요 (e.g., 피곤해요), but you don’t use 해 before -니까. Similarly:

• 좋다 → 좋으니까
• 바쁘다 → 바쁘니까
• 필요하다 → 필요하니까

What’s the difference between -(으)니까 and -아서/어서 in this sentence?