ohu yeoseos sikkaji ilhaeyo.

오후 means afternoon / p.m., and 여섯 시 means six o’clock.

So:

• 오후 = p.m.
• 여섯 시 = 6 o’clock

Together, 오후 여섯 시 = 6 p.m.

Korean often uses 오전 for a.m. and 오후 for p.m.

• 오전 여섯 시 = 6 a.m.
• 오후 여섯 시 = 6 p.m.

Korean usually uses native Korean numbers for hours.

So for hours, you say:

• 한 시 = 1 o’clock
• 두 시 = 2 o’clock
• 세 시 = 3 o’clock
• 네 시 = 4 o’clock
• 다섯 시 = 5 o’clock
• 여섯 시 = 6 o’clock

Even though 육 is the Sino-Korean number for 6, hours normally use the native Korean form 여섯.

By contrast, minutes usually use Sino-Korean numbers:

• 여섯 시 십 분 = 6:10
  not normally 여섯 시 열 분 in standard time-telling

시 is the counter for hours / o’clock.

So:

• 여섯 = six
• 여섯 시 = six o’clock

You need 시 when giving the hour. Without it, 여섯 just means six, not specifically six o’clock.

까지 means until or up to.

In 오후 여섯 시까지 일해요, it marks the time limit:

• 오후 여섯 시까지 = until 6 p.m.
• 일해요 = work

So the whole sentence means (I/you/he/she/we/they) work until 6 p.m.

A useful way to think about 까지 is that it shows the endpoint.

Examples:

• 세 시까지 기다려요. = I wait until 3.
• 집까지 걸어가요. = I walk as far as home / to home.

Korean is generally a subject-object-verb language, and the verb usually comes at the end of the sentence.

So instead of English word order like:

• I work until 6 p.m.

Korean is more like:

• 6 p.m. until work

That is why 일해요 comes last.

This is very normal in Korean, and time expressions often come before the verb.

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

So 오후 여섯 시까지 일해요 could mean:

• I work until 6 p.m.
• He/She works until 6 p.m.
• We work until 6 p.m.
• You work until 6 p.m.

The actual meaning depends on the situation.

If you want to make the subject explicit, you can add it:

• 저는 오후 여섯 시까지 일해요. = I work until 6 p.m.
• 그는 오후 여섯 시까지 일해요. = He works until 6 p.m.

일해요 is the polite present tense form of 일하다 (to work).

Breakdown:

• 일하다 = to work
• 일해요 = work / am working / do work

This -아요 / -어요 style is a very common polite ending in everyday Korean.

So 일해요 is polite, natural, and commonly used in conversation.

It can mean both, depending on context.

Korean present tense often covers both:

• I work
• I am working

So 오후 여섯 시까지 일해요 could mean:

• I work until 6 p.m.
• I’m working until 6 p.m.

In many cases, English chooses one based on context, but Korean does not always make that distinction explicitly.

Because 여섯 시 is the time expression, and 까지 is a particle attached to that phrase.

So it is naturally written as:

• 여섯 시
  • 까지
• 여섯 시까지

There is a space between 여섯 and 시 because they are separate words in the number + counter expression.

You will often see this pattern:

• 세 시에 = at 3 o’clock
• 네 시부터 = from 4 o’clock
• 다섯 시까지 = until 5 o’clock

Yes. In everyday writing, Koreans often use Arabic numerals for time.

So these are both common:

• 오후 여섯 시까지 일해요.
• 오후 6시까지 일해요.

The meaning is the same.

Using numerals is very common in text messages, schedules, signs, and casual writing. Writing it out as 여섯 시 is also correct and may feel a bit more textbook-like or fully spelled out.

Yes, if the context already makes the time clear.

For example:

• 여섯 시까지 일해요. = I work until six.

If everyone already knows you mean evening, you may not need 오후. But if it could be confusing whether it is 6 a.m. or 6 p.m., then adding 오후 makes it clear.

Yes, they do different jobs.

• 에 marks a specific time: at
• 까지 marks an endpoint: until

Compare:

• 오후 여섯 시에 일해요. = I work at 6 p.m.
• 오후 여섯 시까지 일해요. = I work until 6 p.m.

So in this sentence, 까지 is important because the meaning is about continuing work up to that time.

The dictionary form is 일하다. When it becomes polite present tense, it historically comes from 일하여요, but in modern Korean that contracts to 일해요.

So:

• 일하다
• 일하여요
• 일해요 ← the normal modern form

This contraction is very common with 하다 verbs:

• 공부하다 → 공부해요
• 운동하다 → 운동해요
• 일하다 → 일해요

So 일해요 is the normal form learners should use.