manyak hwanseung sigani jjalbeumyeon da-eum jihacheoreul gidarineun geosi deo anjeonhaeyo.

만약 means if or in the event that.

In this sentence, it is not strictly necessary, because the conditional meaning is already expressed by -으면 in 짧으면. So:

• 환승 시간이 짧으면 ... = If the transfer time is short...
• 만약 환승 시간이 짧으면 ... = If the transfer time is short...

Adding 만약 just makes the if meaning more explicit. Korean often uses both together.

환승 시간 is a noun phrase meaning transfer time.

It is made of:

• 환승 = transfer, changing from one bus/train/subway to another
• 시간 = time

So 환승 시간 literally means transfer time or the amount of time available for a transfer.

Here, 이 is the subject particle. It marks 환승 시간 as the thing that is short.

So the structure is:

• 환승 시간이 짧다 = The transfer time is short

If you used 은/는 instead, it would sound more like a topic or contrast:

• 환승 시간은 짧으면 ... would feel less natural here

With 짧다, Korean commonly uses 이/가 for the thing that has that quality.

짧으면 comes from the adjective 짧다 = to be short.

To make a conditional meaning like if it is short, Korean adds -으면 / -면:

• stem: 짧-
• because the stem ends in a consonant, add -으면
• 짧으면 = if it is short

A few examples:

• 길다 → 길면 = if it is long
• 작다 → 작으면 = if it is small
• 짧다 → 짧으면 = if it is short

지하철 can mean subway/metro in general, but in context it can also mean a subway train.

So here:

• 다음 지하철 = the next subway train / the next train

Korean often leaves out a separate word for train when the meaning is obvious from context.

Because 기다리다 means to wait for, and the thing you are waiting for takes the object particle 을/를.

So:

• 다음 지하철을 기다리다 = to wait for the next subway

Here, 다음 지하철 is the thing being waited for, so it gets 을.

기다리는 것 turns the verb 기다리다 (to wait) into a noun-like expression meaning waiting or the act of waiting.

This is called nominalization.

• 기다리다 = to wait
• 기다리는 것 = waiting / the act of waiting

So the sentence is literally structured like:

• Waiting for the next subway is safer

Korean very often uses -는 것 to talk about an action as an idea or activity.

The whole phrase 다음 지하철을 기다리는 것 is treated like a noun, and 이 marks it as the subject of 더 안전해요.

So:

• 다음 지하철을 기다리는 것 = waiting for the next subway
• 이/가 = subject marker
• 더 안전해요 = is safer

Literal breakdown:

• Waiting for the next subway
  • is
    • safer

Yes. 것이 is very often shortened in speech:

• 것이 → 게

So:

• 다음 지하철을 기다리는 것이 더 안전해요
• 다음 지하철을 기다리는 게 더 안전해요

These mean the same thing. The version with 게 sounds more natural and conversational in everyday Korean.

더 means more.

So 더 안전해요 literally means is more safe, which in natural English is usually just is safer.

There is an implied comparison here. Korean does not need to say the other option explicitly. The hidden comparison is something like:

• trying to rush and catch the current train
• making a tight transfer

So the idea is:

• If the transfer time is short, waiting for the next subway is safer.

The dictionary form is 안전하다 = to be safe.

In the polite -아요/어요 style, 하다 becomes 해요:

• 안전하다 → 안전해요

This is a common polite everyday ending. It is respectful but not overly formal.

Compare:

• 안전해 = casual
• 안전해요 = polite everyday speech
• 안전합니다 = more formal

Korean often leaves out the subject when it is obvious from context.

So even though the sentence does not explicitly say you, the meaning can still be:

• you should wait for the next subway
• or more generally, it is safer to wait for the next subway

This kind of subject omission is very common in Korean.

Yes. A fairly literal breakdown would be:

• 만약 = if
• 환승 시간이 = the transfer time
• 짧으면 = is short / if it is short
• 다음 지하철을 = the next subway
• 기다리는 것이 = waiting for it / the act of waiting
• 더 안전해요 = is safer

So a very literal English version would be:

• If the transfer time is short, waiting for the next subway is safer.

That is already very close to the natural English meaning.