ijeon sueobeseo bae-un pyohyeoneul bokseuphae.

Review the expressions learned in the previous class.

Breakdown of ijeon sueobeseo bae-un pyohyeoneul bokseuphae.

• ~을: object particle
• ~에서: location particle
• 수업: class
• 배우다: to learn
• 표현: expression
• 이전: previous
• 복습하다: to review

Questions & Answers about ijeon sueobeseo bae-un pyohyeoneul bokseuphae.

What does 이전 mean and how is it different from 지난 or 저번?

이전 literally means “previous” or “prior” and is a bit more formal.
지난 (“last”) and 저번 (“last time/round”) also refer to something that happened before but sound more colloquial.
You can usually swap them:

• 이전 수업 (formal)
• 지난 수업 (neutral)
• 저번 수업 (casual)

Why is 에서 used after 수업? What does it indicate here?

에서 marks the location or context where an action takes place. In 이전 수업에서 it means “during/in the previous class.”
If you said 수업에, it would imply movement “to the class,” not that something happened inside it.

What is 배운 doing before 표현, and why isn’t it 배웠던 or 배웠을?

배운 is the attributive (pre-nominal) past form of 배우다 (“to learn”). It simply means “learned.”

• 배운 표현 = “expressions that were learned.”
  배웠던 표현 is also correct and adds a nuance of “expressions you used to learn/that you had learned”; it’s slightly more descriptive but not required.
  There is no form 배웠을—the correct more tentative form would be 배웠던.

Why is 표현 followed by 을?

을 is the object particle attached to 표현 (ends with an ‘ㅁ’ consonant) to mark it as the direct object of 복습해 (“review”).
Objects ending in a vowel take 를; those ending in a consonant take 을.

What does 복습해 mean, and what level of politeness is it?

복습해 is the casual (banmal) imperative of 복습하다 (“to review”). It’s like telling friends or close students, “Review!”
For polite/formal speech you’d say 복습하세요 (“Please review”). For a question you might use 복습했어? (“Did you review?”).

Why is there no subject in the sentence?

Korean often omits subjects when they’re obvious from context. Here the implied subject is “you” (the student). In Korean, dropping “you” is natural in instructions.

Could I say 이전 수업에서 배웠던 표현을 복습해 instead? What changes?

Yes. 배웠던 emphasizes that these are expressions you had learned before, giving a slightly fuller background story. Both are correct.

• 배운 표현 = “the learned expressions” (straightforward)
• 배웠던 표현 = “the expressions you had learned” (more descriptive)

Do I need to add 다시 (“again”) to mean “review again”?

No. 복습 itself means “to review” or “study again,” so adding 다시 would be redundant.
다시 복습해 is understandable but not necessary.