geoul apeseo meorireul cheoncheonhi biseosseo.

Korean very often omits the subject when it is already clear from context.

So 거울 앞에서 머리를 천천히 빗었어 can naturally mean:

• I brushed my hair slowly in front of the mirror
• She brushed her hair slowly in front of the mirror
• He brushed his hair slowly in front of the mirror

The listener usually figures out the subject from the situation. In English, you usually need to say the subject, but in Korean, leaving it out is normal.

It breaks down like this:

• 거울 = mirror
• 앞 = front
• -에서 = at/in/from the place where an action happens

So 거울 앞에서 means in front of the mirror.

It describes where the action of brushing happened.

This is a very common question.

• -에 is often used for location/existence or destination
• -에서 is used for the place where an action happens

Here, 빗었어 is an action, so -에서 is the natural choice:

• 거울 앞에서 머리를 빗었어 = brushed hair in front of the mirror

Compare:

• 거울 앞에 있었어 = was in front of the mirror
  (existence/location)
• 거울 앞에서 머리를 빗었어 = brushed hair in front of the mirror
  (action happening there)

In Korean, with body parts, the possessor is often left unstated if it is obvious.

So instead of saying:

• 내 머리를 빗었어

Korean often just says:

• 머리를 빗었어

It still usually means brushed my hair if the subject is understood to be I.

Adding 내 is possible, but it can sound more explicit or emphatic than necessary unless you want contrast, such as:

• 나는 내 머리를 빗었어, 동생 머리가 아니라.
  I brushed my own hair, not my younger sibling’s.

Here, 머리 means hair.

The word 머리 can mean either:

• head
• hair

The meaning depends on the verb and context.

For example:

• 머리가 아파 = My head hurts
• 머리를 빗었어 = I brushed my hair

Because 빗다 means to comb/brush, 머리 is naturally understood as hair here.

-를 is the object marker. It marks 머리 as the thing being brushed.

So:

• 머리를 빗었어 = brushed the hair

In Korean, many verbs take a direct object marked with -을/를, and 빗다 is one of them.

천천히 means slowly. It is an adverb, so it modifies the verb 빗었어.

In this sentence:

• 거울 앞에서 머리를 천천히 빗었어
• 천천히 = slowly
• 빗었어 = brushed

Korean adverbs are fairly flexible in placement, so you can also hear things like:

• 거울 앞에서 천천히 머리를 빗었어
• 머리를 거울 앞에서 천천히 빗었어

But the original sentence is perfectly natural. In general, adverbs often appear before the verb.

빗었어 is the past informal casual form of 빗다 (to comb / to brush).

Breakdown:

• 빗다 = dictionary form
• 빗었- = past stem
• 빗었어 = casual past

This style is used with:

• close friends
• younger people
• family
• casual narration

More polite versions would be:

• 빗었어요 = polite
• 빗었습니다 = formal

Also, 빗다 is behaving regularly here.

Korean is typically a verb-final language.

A very common Korean sentence pattern is:

• subject + place + object + adverb + verb

So in this sentence:

• 거울 앞에서 = place
• 머리를 = object
• 천천히 = adverb
• 빗었어 = verb

In English, the verb usually comes earlier, but in Korean, the verb normally comes at the end of the clause.

Korean word order is more flexible than English, because particles help show each word’s role.

So the original sentence:

• 거울 앞에서 머리를 천천히 빗었어

is natural, but other orders can also work, such as:

• 거울 앞에서 천천히 머리를 빗었어
• 머리를 거울 앞에서 천천히 빗었어

However, not every order sounds equally natural in every context. The original version is a very standard, smooth way to say it.

In general, the verb still stays at the end.

Yes, you could say 머리카락을, because 머리카락 means hair strands / hair more literally.

So:

• 머리를 빗었어
• 머리카락을 빗었어

Both are understandable, but 머리를 빗다 is the more common and natural everyday expression for brushing/combing one’s hair.

Using 머리카락 can sound a bit more literal or specific.

You can make it polite by changing the ending:

• 거울 앞에서 머리를 천천히 빗었어요.

A more formal style would be:

• 거울 앞에서 머리를 천천히 빗었습니다.

So the difference is mainly the speech level, not the basic grammar or meaning.

• 빗었어 = casual
• 빗었어요 = polite
• 빗었습니다 = formal

It can correspond to either to comb or to brush, depending on context.

So 머리를 빗다 can mean:

• to comb one’s hair
• to brush one’s hair

Korean does not always make the same distinction English does between comb and brush. The exact English translation depends on what tool you imagine and how the sentence is being translated.