Learn Hardcore Korean: jeoneun mokmallaseo mureul manhi masyeosseoyo. - I was thirsty, so I drank a lot of water.

It links two clauses with a cause → result relationship: Because I was thirsty, I drank a lot of water. It can feel like “because/so” depending on context.

Why is it 목말라서, not 목말랐어서?

In this cause connector, Korean normally does not put a past marker (-았/었-) before -아서/어서. The time is understood from the main clause. So say 목말라서 … 마셨어요, not 목말랐어서.

Why is it 목말라서, not 목마라서?

It comes from the ㅡ-irregular adjective 마르다 (to be dry). When conjugated, ㅡ drops and you add -아/어:

목마르다 → 목마르 + 아서 → 목말라서.

Is 목말라서 different from 목이 말라서?

Both are natural and mean the same.

목말라서 treats “thirsty” as a single adjective (lexicalized).
목이 말라서 is the more literal “my throat is dry, so…”.
Use whichever you prefer; the nuance difference is tiny.

Can I say 갈증이 나서 instead?

Yes. 갈증이 나서 물을 많이 마셨어요 is “I felt thirst, so I drank a lot of water.” It’s a common alternative to 목말라서.

Why use 저는 and not 제가?

저는 (topic) sets “as for me…” and is neutral here.
제가 (subject) emphasizes that it was specifically “I.”
Both are okay: 저는/제가 목말라서 물을 많이 마셨어요. If you’re contrasting with others, 제가 fits; otherwise 저는 or nothing at all is most natural.

Can I drop 저는?

Yes. Korean often omits the subject when it’s obvious. 목말라서 물을 많이 마셨어요 is perfectly natural.

Why does 물 have -을?

마시다 takes a direct object, so 물 gets the object particle. After a final consonant, use -을 (after a vowel, -를). You can omit it in casual speech: 물 많이 마셨어요 is fine.

Where should 많이 go? Is 많은 물을 마셨어요 okay?

Most natural: 물을 많이 마셨어요 (or with particle dropped: 물 많이 마셨어요).
많은 물을 마셨어요 is grammatical but feels more written/formal or contrastive (“a large amount of water”).
Avoid 많이 물을 마셨어요; adverbs usually don’t come between a noun and its particle.

Why 마셨어요 and not 마시었어요?

It’s the standard contraction: 마시 + 었 + 어요 → 마셨어요.

Can I use 먹다 instead of 마시다 for water?

Standard is 물(을) 마시다. 물 먹다 is heard colloquially in some regions, but it can also mean “to fail at something” in an idiom, so stick with 마시다.

Isn’t there a tense mismatch—present-looking 목말라- with past 마셨어요?

No. In -아서/어서 reason clauses, Korean typically doesn’t mark past; the timing is inherited from the main clause. So 목말라서 … 마셨어요 means “I was thirsty, so I drank.”

What’s the difference between -아서/어서 and 그래서?

-아서/어서 directly links two clauses: 목말라서 물을 많이 마셨어요.
그래서 connects sentences: 목말랐어요. 그래서 물을 많이 마셨어요.
Meaning is similar; 그래서 adds a clearer pause between cause and result.

Can I use -니까 instead of -아서/어서?

Yes: 목마르니까 물을 많이 마셨어요.
Nuance: -니까 can sound a bit more direct/justificatory and is especially common with commands/requests (e.g., 목마르니까 물 좀 주세요). -아서/어서 often feels like a natural cause-effect explanation.

What politeness level is this? How would I change it?

Polite: 저는 목말라서 물을 많이 마셨어요.
Casual: 나 목말라서 물 많이 마셨어.
Formal (deferential): 저는 목말라서 물을 많이 마셨습니다.

Any pronunciation tips?

목말라서 → [몽말라서] (the final ㄱ in 목 nasalizes before ㅁ).
마셨어요 → [마셔써요].
물을 → [무를] (the ㄹ flaps between vowels).

Is the spacing right? Why not 목 말라서?

Write 목말라서 as one word because 목마르다 is a single adjective and -아서 attaches to the verb/adjective stem. If you use the literal phrasing, write 목이 말라서 with spaces.

Does 너무 많이 mean “very much” or “too much”?

By default 너무 means “too (excessively).” So 물을 너무 많이 마셨어요 usually means “I drank too much water.” In casual speech 너무 can mean “very,” but with 많이 it’s commonly understood as “too much.”

Can I answer a “why” question with just 목말라서요?

Yes. As a standalone explanation it’s natural:
— 왜 물을 그렇게 많이 마셨어요?
— 목말라서요.

Is -서 here the same as the location particle -에서?

No. -아서/어서 is a clause connector meaning “because/so,” while -에서 is a location/source marker (“at/from”). They’re different endings.