sueop jeone gwajereul jechulhaeya haeyo.

전에 is a time particle that attaches to a noun to mean “before (noun).”

• 수업 (class) + 전에 = 수업 전에 (“before class”).
• It turns 수업 into an adverbial phrase indicating when something happens.
• You can likewise use 후에 (“after”) as in 수업 후에 = “after class.”

과제 means “assignment” or “homework.”

• The particle 를 marks it as the direct object of the verb.
• In Korean, objects generally need 을/를 to show what’s being acted upon.
• So 과제를 tells us “the assignment” is what you must submit.

The pattern ~아/어야 해요 expresses obligation (“must” or “have to”).
Formation steps:

1. Take the verb stem (drop -다 from the dictionary form).
2. If the last vowel of the stem is ㅏ or ㅗ, add -아야 해요; otherwise add -어야 해요.
   
   • 제출하다 → stem 제출하- → 제출하 + 아야 해요 = 제출해야 해요.
3. This literally means “it’s necessary to submit.”

Yes. Both express “have to”:

• ~아/어야 해요 comes from 하다 (“to do”).
• ~아/어야 돼요 comes from 되다 (“to become”).
  They’re largely interchangeable in speech.
• 해야 해요 is slightly more neutral/polite.
• 해야 돼요 can feel a bit more casual.

Yes, you can say 과제를 내야 해요.

• 내다 means “to turn in” or “to hand in” and is common in everyday contexts.
• 제출하다 is more formal/offical (“to submit”).
  In most classroom conversations, they’re used interchangeably.

Korean follows Subject-Object-Verb (SOV) order, so the verb always ends the clause.
You can shuffle time and object phrases before that—for example:

• 수업 전에 과제를 제출해야 해요.
• 과제를 수업 전에 제출해야 해요.
  But the verb phrase 제출해야 해요 stays at the very end.

-해야 해요 is polite (해요체), suitable for everyday situations (e.g., teacher–student, coworkers).

• More formal (합니다체): 수업 전에 과제를 제출해야 합니다.
• Less formal/casual (해체): 수업 전에 과제를 제출해야 해.