eojeneun neomu pigonhaeseo angyeongeul sseun chaero jamosdo an garaipgo jamdeureosseo.

어제는 means as for yesterday or yesterday with a topic nuance.

Using 는 does a little more than just mark time:

• It sets yesterday as the topic/background for the sentence.
• It can give a slight contrastive feeling, like yesterday in particular.

So:

• 어제 너무 피곤해서... = Yesterday, because I was so tired...
• 어제는 너무 피곤해서... = As for yesterday / Yesterday especially, I was so tired...

In many cases, both are natural, but 는 helps frame the whole situation.

Here it basically means so tired or very tired, with the idea that this tiredness led to what happened next.

The grammar -아서/어서 often shows a cause:

• 피곤해서 = because I was tired / being tired, so...

So 너무 피곤해서 is not just describing tiredness. It means:

• I was so tired that...
• Because I was very tired...

Also, in modern spoken Korean, 너무 is often used simply as an intensifier, not only in the strict English sense of too.

Korean uses different verbs for wearing different things.

For glasses, hats, and masks, Korean often uses 쓰다:

• 안경을 쓰다 = to wear glasses
• 모자를 쓰다 = to wear a hat

This is just something you have to learn as a set expression.

Some common clothing/body-item verbs:

• 입다 = wear clothes
• 신다 = wear shoes
• 쓰다 = wear on the head/face area, including glasses
• 끼다 = wear rings/gloves/glasses in some contexts, though 안경을 쓰다 is the standard basic expression

So in this sentence, 안경을 쓴 means having glasses on.

-ㄴ/은 채로 means in the state of having done X, while still X, or without changing that state.

So:

• 안경을 쓴 채로 = with my glasses still on
• literally, in the state of wearing glasses

This pattern emphasizes that the earlier state remained unchanged during the main action.

More examples:

• 문을 연 채로 잤다 = slept with the door open
• 불을 켠 채로 나갔다 = left with the light still on
• 신발을 신은 채로 들어왔어요 = came in with shoes still on

In your sentence, it highlights that the speaker fell asleep without taking the glasses off.

Because -채로 usually attaches to a form that describes a resulting state.

• 쓰는 is the present adnominal form: wearing
• 쓴 is the adnominal form that works here to show the state resulting from putting them on

So:

• 안경을 쓴 채로 = in the state of having glasses on

This is the natural fixed pattern.

Compare:

• 안경을 쓰고 잤다 = slept wearing glasses
• 안경을 쓴 채로 잤다 = slept with glasses still on

Both are possible, but -채로 more strongly emphasizes that the state remained unchanged.

Here 도 adds the meaning of even.

So:

• 잠옷을 안 갈아입고 = without changing into pajamas
• 잠옷도 안 갈아입고 = without even changing into pajamas

The speaker is emphasizing how tired they were: they did not do even that basic thing before falling asleep.

With negatives, 도 often gives this not even feeling:

• 물도 안 마셨어 = I didn’t even drink water
• 밥도 안 먹었어 = I didn’t even eat

So 잠옷도 안 갈아입고 makes the sentence sound a little more vivid and expressive.

갈아입다 means to change clothes or to change into something else.

In Korean, the new clothing item can be marked directly as the object:

• 잠옷을 갈아입다 = change into pajamas

In casual speech, particles are often omitted when the meaning is obvious, and sometimes learners see examples where the object feels a bit compressed in fast conversational style. In this sentence, the meaning is clearly:

• (잠옷으로) 갈아입다 / 잠옷을 갈아입다
• in natural English: change into pajamas

So 잠옷도 안 갈아입고 means the speaker didn’t even change into pajamas.

Here -고 links actions, but in this kind of sentence it often works like and or without doing X, then...

So:

• 잠옷도 안 갈아입고 잠들었어 = I fell asleep without even changing into pajamas

This is very common in Korean:

• 세수도 안 하고 잤어 = I slept without even washing my face
• 불도 안 끄고 나갔어 = I left without even turning off the light

So although -고 often simply means and, in context it can naturally be translated as without doing.

잠들다 means to fall asleep, while 자다 means to sleep.

So:

• 잠들었어 = fell asleep
• 잤어 = slept

In this sentence, 잠들었어 is better because the speaker is describing the moment/result:

• they were so tired
• they didn’t change into pajamas
• they fell asleep like that

If you used 잤어, it would focus more on the sleeping itself, not the drifting off.

Yes, the subject is omitted, which is very normal in Korean.

From context, the implied subject is I:

• (나는) 어제는 너무 피곤해서... 잠들었어
• I was so tired yesterday that... I fell asleep

Korean often leaves out subjects and objects when they are obvious from context. Native speakers do this all the time, especially in conversation.

잠들었어 is casual/informal speech, often used with friends, family, or in diary-style narration.

A polite version would be: 어제는 너무 피곤해서 안경을 쓴 채로 잠옷도 안 갈아입고 잠들었어요.

The grammar stays the same; only the final ending changes:

• 잠들었어 = casual
• 잠들었어요 = polite

Yes, very often it can.

-채로 is neutral in grammar, but in real usage it frequently appears when someone stays in a state they normally would have changed:

• 화장을 한 채로 잤다 = slept with makeup still on
• 불을 켠 채로 잤다 = slept with the light still on
• 안경을 쓴 채로 잠들었다 = fell asleep with glasses still on

So it often suggests:

• the state continued unintentionally
• the person was careless, exhausted, distracted, or forgot

In your sentence, that nuance matches the idea of being extremely tired.

A helpful breakdown is:

• 어제는 = as for yesterday
• 너무 피곤해서 = because I was so tired
• 안경을 쓴 채로 = with my glasses still on
• 잠옷도 안 갈아입고 = without even changing into pajamas
• 잠들었어 = I fell asleep

So the flow is:

As for yesterday, because I was so tired, I fell asleep with my glasses still on, without even changing into pajamas.

That is a very natural Korean sentence structure: background first, then cause, then the state/action details, and finally the main verb at the end.