Learn Hardcore Korean: jeoneun maeil daneoreul bokseuphaeyo.

저 is the humble/polite form of “I,” used when speaking politely or formally. 나 is the casual/informal form of “I,” typically used with close friends or family. By saying 저는, you’re both introducing yourself as the topic (“as for me...”) and signaling polite speech.

Why do we attach -는 to 저 (as in 저는) instead of the subject particle -가?

-는 is the topic particle, marking 저 as the topic (“as for me”). It’s often used in general statements or habitual actions. -가 is the subject particle, used for emphasis or when presenting new information. Saying 저는 (vs. 제가) gives a natural, neutral tone for “I (habitually) ….”

What part of speech is 매일, and why is there no particle like -에 after it?

매일 is an adverb meaning “every day.” Adverbs directly modify verbs and do not require particles. If you add -에 (making 매일에), it becomes a locative/dative expression (“at every day”), which isn’t standard for expressing frequency.

Can 매일 appear in a different position in the sentence?

Yes. Korean word order is flexible. You could also say:

저는 단어를 매일 복습해요.
매일 저는 단어를 복습해요.
But placing an adverb like 매일 close to the verb is most common.

Why do we use 단어를, and what is the function of -를?

단어 means “word/vocabulary,” and -를 is the object particle. It marks 단어 as the direct object of 복습해요 (to review), showing what is being reviewed.

Do we have to use -를 after 단어, or can we omit it?

In casual spoken Korean, learners may drop particles and say 저 매일 단어 복습해요, and native speakers will still understand. However, using 단어를 is grammatically correct and clearer—especially in writing or more polite/formal contexts.

How do we get from the dictionary form 복습하다 to 복습해요?

복습하다 is a compound verb (Sino-Korean noun 복습 + 하다, “to do”). To form the present tense polite, you:

Remove -다 from 하다.
Attach -해요.
Result: 복습해요 (“(I) review”).

What’s the difference between 복습해요 and 복습하고 있어요?

복습해요 expresses a habitual or regular action (“I review every day”).
복습하고 있어요 is the present progressive (“I am reviewing right now”).

Is 복습하다 the same as 공부하다, and can I say 단어 공부해요 instead?

공부하다 means “to study” in general (learning new material or practicing), while 복습하다 specifically means “to review material already learned.” Saying 단어 공부해요 (“I study vocabulary”) is correct but doesn’t emphasize “review” the way 단어를 복습해요 does.

Why is the sentence in the -요 form (복습해요) instead of the formal -합니다 form (복습합니다)?

The -해요 ending is polite/informal (“해요 style”), common in daily conversation. The -합니다 ending is formal/polite (“합니다 style”), used in speeches, presentations, or when you need extra formality. Here, 복습해요 fits a friendly yet polite tone.