bae-uga mudaeeseo janeun cheokhaesseo.

-는 척하다 means to pretend to do something or to act as if one is doing something.

So:

• 자다 = to sleep
• 자는 척하다 = to pretend to sleep / to act like one is sleeping

In this sentence, 자는 척했어 means the person pretended to be sleeping.

This pattern is very common with action verbs:

• 먹는 척하다 = pretend to eat
• 듣는 척하다 = pretend to listen
• 아는 척하다 = pretend to know

Because 척하다 needs the verb in a modifier form before it.

With action verbs, the usual pattern is:

• verb stem + 는 척하다

So:

• 자다 → 자는 척하다
• 먹다 → 먹는 척하다
• 읽다 → 읽는 척하다

You cannot normally put the dictionary form directly before 척하다, so 자다 척했어 is not grammatical.

Because the past tense is marked on 척하다, not on the pretended action itself.

Structure:

• 자는 척했어
• literally: did pretending-to-sleep

The -는 form here is not showing present tense in the same way English does. It is the standard form used before 척하다 with action verbs.

So the sentence means that the pretending happened in the past.

무대 means stage, and 에서 marks the place where an action happens.

So:

• 무대에서 = on the stage / at the stage, as the location of the action

Korean often uses:

• 에 for destination or static location
• 에서 for the place where an action occurs

Since pretending to sleep is an action happening on the stage, 에서 is the natural choice.

Compare:

• 무대에 올라갔어 = went up onto the stage
• 무대에서 잤어 = slept on the stage
• 무대에서 자는 척했어 = pretended to sleep on the stage

가 is the subject marker, while 는 is the topic marker.

In this sentence, 배우가 simply identifies the actor as the subject of the action:

• 배우가 무대에서 자는 척했어

Using 배우는 would also be possible in some contexts, but it would give a different nuance, such as setting up the actor as a topic or adding contrast.

Very roughly:

• 배우가 = the actor did it
• 배우는 = as for the actor, they did it / the actor, on the other hand...

In an isolated sentence like this, 가 is very natural.

No. 배우 is generally gender-neutral and can mean actor or actress depending on context.

If Korean speakers want to specify gender, they can add words like:

• 남자 배우 = male actor
• 여자 배우 = actress / female actor

But 배우 by itself does not force a male meaning.

했어 is casual, informal speech.

It is the past form of 하다 in the 반말 style, which is used with:

• close friends
• younger people
• children
• situations where casual speech is appropriate

More polite versions would be:

• 배우가 무대에서 자는 척했어요.
• 배우가 무대에서 자는 척했습니다.

So the grammar is the same; only the speech level changes.

Yes. 척하다 strongly implies pretending, so the normal understanding is that the actor was not really sleeping.

So 자는 척했어 means the actor acted like they were asleep.

That is exactly what 척하다 adds: a sense of appearance without reality.

Yes. Korean word order is more flexible than English, as long as the particles still show each word’s role.

For example, these are all possible depending on context:

• 배우가 무대에서 자는 척했어.
• 무대에서 배우가 자는 척했어.

Both still mean basically the same thing. The difference is usually about focus or flow, not core grammar.

Because of the particles:

• 가 marks the subject
• 에서 marks the location

the sentence remains understandable even if the order changes.

Because 자는 and 척했어 are written as separate units.

• 자는 = modifier form of 자다
• 척하다 = a verb meaning to pretend
• 척했어 = past casual form of 척하다

So the standard spacing is:

• 자는 척했어

not:

• 자는척했어

You can think of it as pretending being the main verb, and 자는 modifying it.

In practice, it can cover both ideas.

Because 자다 means to sleep, 자는 척하다 can naturally be understood as:

• pretended to sleep
• pretended to be sleeping
• acted like they were asleep

English chooses among those depending on style, but the Korean expression comfortably covers that whole area.