bameneun keopireul masiji malgo mureul masyeoyo.

밤에 means at night.
Adding 는 makes it 밤에는, which adds contrast or topic emphasis.

So 밤에는 can feel like:

• as for at night
• at night, though
• when it comes to nighttime

In this sentence, it suggests a contrast such as:

• At night, don’t drink coffee; drink water.
• (Maybe in the daytime it is different, but) at night, drink water instead.

So 에는 here is 에 + 는.

The 는 is the topic/contrast marker.

It often does one of these jobs:

• marks the topic of the sentence
• adds a contrastive feeling
• highlights a specific situation

Here it strongly sounds contrastive. The speaker is not just saying something happens at night; they are saying when it is night, this is what you should do.

Compare:

• 밤에 커피를 마시지 말고 물을 마셔요. = At night, don’t drink coffee; drink water.
• 밤에는 커피를 마시지 말고 물을 마셔요. = At night, specifically, don’t drink coffee; drink water.

The second one feels more like a rule or recommendation for that time.

Because both 커피 and 물 are direct objects of the verb 마시다 (to drink).

• 커피를 마시다 = to drink coffee
• 물을 마시다 = to drink water

The object particle is:

• 을 after a consonant
• 를 after a vowel

So:

• 커피 ends in a vowel sound → 커피를
• 물 ends in a consonant sound → 물을

-지 말고 means:

• don’t do X, and instead...
• rather than doing X...
• not X, but Y

In this sentence:

• 마시지 말고 = don’t drink (it), but...

So the full pattern is:

• 커피를 마시지 말고 물을 마셔요.
• Don’t drink coffee; drink water instead.

This pattern is very common when giving advice, instructions, or polite commands.

Examples:

• 늦게 자지 말고 일찍 자요.
  Don’t go to bed late; go to bed early.

• 전화하지 말고 문자해요.
  Don’t call; send a text.

It comes from the verb 마시다 (to drink).

Breakdown:

• 마시- = verb stem
• -지 말다 = do not do
• -고 = and / and then / but rather

So:

• 마시다
• 마시지 말다 = do not drink
• 마시지 말고 = don’t drink (it), but...

This is a set grammar pattern, so it is best learned as:

• Verb stem + 지 말고

Examples:

• 먹지 말고 = don’t eat (it), but...
• 가지 말고 = don’t go, but...
• 보지 말고 = don’t look/watch, but...

Because 안 마시고 means not drinking, and..., but it does not give the same clear command meaning as 마시지 말고.

Compare:

• 커피를 안 마시고 물을 마셔요.
  This sounds more like a description: You don’t drink coffee, and you drink water.

• 커피를 마시지 말고 물을 마셔요.
  This means: Don’t drink coffee; drink water instead.

So -지 말고 is the correct form when you want to tell someone not to do one thing and to do another instead.

Both come from 마시다, but 마시어요 contracts to 마셔요 in normal Korean.

So:

• 마시어요 → 마셔요

This kind of contraction is very common and natural.

Other examples:

• 보다 → 보아요 → 봐요
• 쓰이다 → 쓰이어요 → 쓰여요
• 마시다 → 마시어요 → 마셔요

So 마셔요 is the normal everyday form.

Because only the final verb needs the sentence-ending style.

In Korean, when you connect actions or clauses, earlier verbs often take a connective form, and the final verb carries the tense/style/politeness.

Here:

• 마시지 말고 = connected clause
• 마셔요 = final clause, so it gets the polite ending -요

This is very normal in Korean.

A similar pattern:

• 학교에 가서 공부해요.
  Go to school and study.

Only the last verb shows the full sentence ending.

It is most naturally understood as polite advice or a polite instruction.

Because it ends in -요, it sounds polite and not too harsh. Depending on context, it could be:

• advice from a doctor or friend
• a recommendation
• a polite command

So it is softer than a blunt order, but it still tells the listener what to do.

If you wanted a stronger, more direct command, you could say:

• 밤에는 커피를 마시지 말고 물을 마셔라.
  much more direct / authoritative

If you wanted a very formal style:

• 밤에는 커피를 마시지 말고 물을 마시세요.
  polite instruction, often very common in advice

Because Korean often omits the subject when it is understood from context.

In English, you usually need something like:

• You shouldn’t drink coffee at night; drink water.

In Korean, the you is often left out because it is obvious that the speaker is addressing the listener.

So the hidden subject is something like:

• (당신은 / 너는)

But actually saying 당신은 here would usually sound unnatural in normal conversation. Korean prefers to omit it.

Yes. That would be very natural:

• 밤에는 커피를 마시지 말고 물을 마시세요.

This sounds a little more clearly like advice or an instruction directed at the listener.

Compare:

• 마셔요 = polite, but can sound a bit softer or more conversational depending on context
• 마시세요 = polite and explicitly directed to the listener as a request/instruction

Both are possible, but 마시세요 is especially common for giving advice.

Because 마시다 is the Korean verb used for drinking liquids.

So you use 마시다 with things like:

• 커피를 마시다 = drink coffee
• 물을 마시다 = drink water
• 차를 마시다 = drink tea
• 우유를 마시다 = drink milk

In English, we also say drink for both coffee and water, so this part matches English quite well.

Yes, in conversation people often drop object particles if the meaning is still clear.

So you may hear:

• 밤에는 커피 마시지 말고 물 마셔요.

This is common in speech.

But for learners, the full version is very useful:

• 밤에는 커피를 마시지 말고 물을 마셔요.

Using the particles helps you see the grammar clearly, and it is fully correct.

Somewhat, yes, but the original order is very natural.

Standard order:

• 밤에는 커피를 마시지 말고 물을 마셔요.

Korean often puts time expressions early, so 밤에는 at the front is very normal.

You might also hear variations for emphasis, but not all of them sound equally natural. The original sentence is a very good default pattern:

• time expression + object + verb + object + verb

For learners, it is best to keep this order until you are more comfortable with Korean emphasis patterns.

A casual version could be:

• 밤에는 커피 마시지 말고 물 마셔.

A slightly more polite instruction:

• 밤에는 커피 마시지 말고 물 마셔요.

A very polite or recommendation-like version:

• 밤에는 커피를 마시지 말고 물을 마시세요.

So the main grammar stays the same; only the ending changes depending on politeness level.