munjega saenggimyeon baro allyeo juseyo.

문제가 uses the subject marker 가 because the verb 생기다 means to arise / to occur. In other words, the problem is the thing that comes up.

• 문제가 생기다 = a problem occurs
• 문제를 해결하다 = solve a problem

So 문제를 생기다 is not correct, because 생기다 does not take a direct object here.

As for 문제는, that would mark problem as the topic and often adds contrast or emphasis. In this sentence, 문제가 is the most natural neutral choice.

Here, 생기다 means to arise, to occur, or to come up.

It is a very common verb with things like:

• 문제가 생기다 = a problem arises
• 기회가 생기다 = an opportunity comes up
• 변화가 생기다 = a change occurs

So this sentence is using a very natural Korean expression: 문제가 생기면 = if a problem comes up.

-면 is a conditional ending meaning if or sometimes when.

It is attached to the verb stem:

• 생기다 → stem 생기-
• 생기 + 면 → 생기면

So 문제가 생기면 means if a problem arises or when a problem arises.

It can feel like both.

In this sentence, 문제가 생기면 바로 알려 주세요 can be understood as:

• If a problem comes up, please let me know right away
• When a problem comes up, please let me know right away

The Korean -면 often covers both ideas. It gives a general condition: whenever that situation happens.

바로 means right away, immediately, or directly.

It adds urgency:

• 문제가 생기면 알려 주세요 = Please let me know if a problem comes up.
• 문제가 생기면 바로 알려 주세요 = Please let me know right away if a problem comes up.

So 바로 tells the listener not to wait.

It comes from 알리다, which means to inform / to let someone know.

The structure is:

• 알리다 → verb stem 알리-
• 알리어 주다 → contracted to 알려 주다
• 알려 주세요 = please let me know / please inform me

A key point: this is from 알리다, not from 알다.

So 알려 주세요 literally has the sense of please do the favor of informing me/us.

By itself, 주세요 means please give [it to me]. But after a verb form like 알려, it works as a polite request pattern:

• 알려 주세요 = please let me know
• 도와 주세요 = please help me
• 기다려 주세요 = please wait

So here, 주세요 does not mean a literal physical giving. It makes the request sound polite and natural.

This is polite standard Korean, often called 해요체.

It is appropriate for:

• coworkers
• customers
• people you do not know well
• everyday polite conversation

Related versions:

• 문제가 생기면 바로 알려 줘. = casual
• 문제가 생기면 바로 알려 주십시오. = more formal

So 알려 주세요 is polite and very commonly used.

Korean often leaves out words that are understood from context.

So 알려 주세요 usually means:

• please let me know
• please let us know
• please inform the relevant person/team

If you want to make it explicit, you can say:

• 저에게 바로 알려 주세요. = Please let me know right away.
• 저희에게 바로 알려 주세요. = Please let us know right away.

Both are natural, but the nuance is slightly different.

• 문제가 생기면 = if a problem arises / if something comes up
• 문제가 있으면 = if there is a problem

생기면 focuses on a problem appearing or developing. 있으면 focuses on the existence of a problem.

In many real situations, both work, but 문제가 생기면 often sounds a little more like if anything goes wrong.

Yes. It is very natural in workplaces, customer service, instructions, and general polite communication.

For example:

• a manager to a staff member
• a teacher to a student
• a company to a client
• a host to a guest

It sounds polite, clear, and practical.

Yes.

More casual:

• 문제 생기면 바로 알려 줘.

More formal:

• 문제가 생기면 바로 알려 주십시오.

A few notes:

• In casual speech, particles like 가 are often dropped, so 문제 생기면 is common.
• In careful or standard speech, 문제가 생기면 is better.

In real life, both 알려 주세요 and 알려주세요 are common.

For learners, 알려 주세요 is a very safe and clear way to write it, because it shows the structure:

• 알려
  • 주세요

So even if you see the one-word version often in messages or signs, the spaced version is perfectly normal and useful to learn.