Learn Hardcore Korean: jeoneun mulman masyeoyo.

저는 breaks down into 저 (the humble form of “I”) + topic marker 는. It marks “as for me…” and sets you up as the topic of the sentence. We use 저 in polite speech; 나 is casual and only for close friends or people younger than you.

What does 물만 mean, and why isn’t there a separate object marker like -을/를?

만 is a particle meaning “only.” When you attach 만 to 물 (water), you get 물만 = “only water.” In colloquial Korean, 만 can replace the object marker -을/를, so you drop 을/를 and say 물만 instead of 물을만. (In very formal writing you might see 물만을, but it’s rare in speech.)

Why is the verb 마시다 conjugated as 마셔요 here?

마시다 (to drink) follows the polite present tense -아요/어요 pattern. Because 마시- ends in the vowel ㅣ, you add -어요, which contracts to -여요, giving 마셔요. This ending is informal polite, suitable for everyday conversation.

How would you say “I drink water” without implying “only”?