Learn Hardcore Korean: chinguga bonaen munjareul baro hwaginhaeyo. - I immediately check the text message my friend sent.

가 is the subject marker that introduces new or specific information. In this sentence, 친구가 marks “friend” as the subject of the verb 보낸 in the relative clause. Using 는 would topicalize “friend,” giving it a contrastive or general-topic nuance, which isn’t the focus here.

How does 친구가 보낸 문자를 function in this sentence?

This is a noun phrase built with a relative clause. It breaks down as:

친구가 (subject of the clause)
보낸 (past-tense attributive form “sent”)
문자를 (object of the clause)
Together, 친구가 보낸 문자를 means “the text that a friend sent,” modifying the noun 문자 before the main verb.

What is the form 보낸, and why isn’t it 보냈다 or 보내는?

보낸 is the past-tense attributive (modifier) form of 보내다. You use it to describe a noun (“the text that was sent”).
보냈다 is the declarative past form, which ends a sentence (“sent”).
보내는 is the present tense attributive form (“the text that is being sent” or “the text that a friend sends”). Using 보낸 correctly expresses that the sending already happened.

What role does the particle -를 play in 문자를?

The particle -를 marks 문자 as the direct object of the verb 보낸 in the relative clause. Without -를, you wouldn’t clearly indicate that the text is what was sent.

What does 바로 mean, and where can it be placed in the sentence?

바로 means “immediately,” “right away,” or “at once.”
It’s an adverb modifying 확인해요 (“check/confirm”).
You can place it before the verb or right before the object:
- 문자를 바로 확인해요
- 바로 문자를 확인해요
  Both orders are acceptable, though placing adverbs immediately before the verb is common.

Why does the sentence end with 확인해요, and what level of politeness is this?

확인해요 is the present-tense, polite ending (–요 form) of 확인하다. It’s everyday polite speech—friendly but respectful—suitable for casual conversations where you’re not on very intimate terms (e.g., with acquaintances or colleagues).

Why is the word order Subject–Object–Verb (SOV) here instead of English’s SVO?

Korean syntax follows Subject–Object–Verb:

친구가 (subject)
문자를 (object)
바로 확인해요 (verb phrase)
Reordering this into Subject–Verb–Object would sound unnatural in Korean, as verbs almost always come last.

Can you drop 친구가 if the context is clear?

Yes. If it’s already clear whose text you’re talking about, you can say:

보낸 문자를 바로 확인해요
문자를 바로 확인해요
Korean often omits subjects (and even objects) when they’re understood from context.