Learn Hardcore Korean: momi pigonhaeseo iljjik jasseoyo. - My body was tired, so I went to bed early.

Koreans often describe physical conditions by making the body the subject. Saying 몸이 피곤해요 (literally my body is tired) feels more natural than 저는 피곤해요 (“I am tired”) when talking about being physically tired.

What does the connective -아서/어서 in 피곤해서 indicate?

The ending -아서/어서 attaches to verb or adjective stems to mean “because” or “so.” Here 피곤하- + -어서 = 피곤해서, showing that being tired is the reason for sleeping early.

Can we say 피곤하니까 instead of 피곤해서?

Yes. -니까 also means “because.”
• 피곤하니까 일찍 잤어요 is perfectly fine.
• -니까 often sounds a bit more formal or direct, while -아서/어서 is more conversational.

Why is 일찍 placed before 잤어요?

In Korean sentence structure, adverbs like 일찍 (early) generally come right before the verb or adjective they modify. So 일찍 잤어요 = slept early.

What’s the nuance if we use 잠들었어요 instead of 잤어요?

• 자다 = to sleep (general action of sleeping).
• 잠들다 = to fall asleep (focus on the moment you drift off).
If you say 잠들었어요, you’re highlighting the act of falling asleep early.

What level of politeness is the ending -었어요 in 잤어요?

The -았/었어요 ending is the polite informal style (존댓말). It’s the standard polite form you use with people you’re not extremely close to or in everyday polite conversation.

Could I drop 몸이 and just say 피곤해서 일찍 잤어요?

Yes. Korean often omits the subject when it’s clear from context. 피곤해서 일찍 잤어요 still clearly means I was tired, so I slept early.

What’s the difference between using -고 and -아서/어서 here (e.g., 몸이 피곤하고 일찍 잤어요)?

• -고 simply lists two states or actions: “was tired and slept early.”
• -아서/어서 explicitly marks a cause-and-effect relationship: “because I was tired, I slept early.”