Learn Hardcore Korean: chingudo hangugeoreul gongbuhaeyo.

도 is the “also/too” particle. When attached to 친구, it indicates that the friend, in addition to someone else, is studying Korean. In Korean, 도 replaces other case markers (like 이/가 or 은/는) on that noun.

Why is 를 used after 한국어?

Because 공부하다 is a transitive verb that takes a direct object, Korean uses the object particle 를 (not 을, which follows consonant-ending nouns). 한국어 ends with a vowel, so it correctly pairs with 를.

Why does 공부해요 end in -해요, and what does that tell me about tense and politeness?

공부해요 is the polite informal present-tense form of 공부하다. The -해요 ending signals present tense and a respectful-but-casual speech level (해요체).

What’s the difference between using 공부해요 and 공부합니다?

공부해요 (해요체) is polite informal and common in everyday conversation. 공부합니다 (합쇼체 or 합니다체) is polite formal, used in announcements, speeches, or when talking to someone of higher status.

Why don’t we see a possessive pronoun like 제 친구 or 내 친구 here?

Korean often drops possessive pronouns when the meaning is clear from context. 친구 alone can mean “my friend.” If you want to be explicit and polite, you could say 제 친구도 한국어를 공부해요.

Can I attach 도 to 한국어 instead? How would that change the meaning?

Yes. 한국어도 공부해요 means “(I) study Korean too,” implying that Korean is an additional subject you study. The placement of 도 shows which element (“friend” or “Korean”) is being highlighted as “also.”

Why does the verb 공부해요 come at the end of the sentence?

Korean follows a Subject-Object-Verb (SOV) word order, so verbs are placed at the end, unlike English’s typical Subject-Verb-Object order.