Learn Hardcore Korean: boksahan seoryureul gyosunimkke jechulhaesseoyo. - I submitted the copied documents to the professor.

복사한 is the active attributive form of the verb 복사하다, meaning “(I) copied.” It literally describes “the documents that I copied.”
복사된 is the passive attributive form “the documents that were copied,” with a focus on the result rather than who did it.
Both are grammatically correct; use 복사한 서류 when you want to highlight that you (the speaker) performed the copying.

What role does -한 play in 복사한 서류?

In Korean, you turn a verb into an adjective-like modifier by adding -ㄴ/-은 (for past actions) or -는 (for ongoing/future) to the verb stem.
복사하다 → stem 복사하- → remove 다, add -ㄴ → 복사한.
This makes it “[the] copied documents,” where 복사한 directly modifies 서류.

Why is the object marker 를 attached to 서류?

서류를 marks 서류 as the direct object of the verb 제출하다 (“to submit”).
In SOV word order, the object comes before the verb and must carry -를/을 to show it’s being acted upon.

Why is 교수님께 used, rather than 교수님을 or 교수님에게?

께 is an honorific dative particle, used when giving, sending, or submitting something to someone deserving respect (like a professor).
교수님을 제출했어요 wouldn’t make sense, because -을/를 marks direct objects, not recipients.
교수님에게 is neutral dative; you can use it, but 께 is more polite.

Can I replace 교수님께 with 교수님한테?

한테 is casual dative, typically used in informal contexts among equals or with juniors.
With someone of higher status or in polite/formal speech, prefer 께 or 에게.

What’s the difference between 제출하다 and 내다?

제출하다 is a more formal verb meaning “to submit” (e.g. official documents, applications, reports).
내다 can also mean “to hand in” or “to turn in,” and is more colloquial (e.g. homework: 숙제를 내다).

Why is the sentence in the past tense 제출했어요? Could I say 제출합니다 instead?

-했어요 is the polite past ending. It indicates “I submitted.”
If you want a present/polite form (more formal or for announcements), use 제출합니다 (“I submit” or “I am submitting”).
You can also use the more formal past: 제출했습니다.

Where is the subject “I” in this sentence?

Korean often omits the subject when it’s clear from context.
Implicitly, 저 (“I” formal) or 내가/제가 is the subject.
If you needed to be explicit: (제가) 복사한 서류를 교수님께 제출했어요.

Could I rephrase using a connective, like “and then”?

Yes. You can show sequence with -아서/-어서 or -고:

서류를 복사하고 교수님께 제출했어요.
서류를 복사해서 교수님께 제출했어요.
Both mean “I copied the documents and then submitted them to the professor.” The nuance difference is minor: -아서/어서 slightly emphasizes the sequence.

Can I change the word order to 교수님께 복사한 서류를 제출했어요?

Yes. Korean allows flexible word order as long as particles stay attached. Placing 교수님께 first might emphasize “to the professor.” The meaning remains “I submitted the copied documents to the professor.”