V+고서

Overview

The connective ending -고서 is used to link two clauses, indicating that the action or state described in the first clause is completed before the action or state in the second clause begins. It emphasizes a clear sequential relationship between the two events.

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Usage

-고서 primarily functions to express a temporal sequence, where the first action must be finished before the second action can occur. While similar to -고, -고서 often carries a stronger nuance of completion or prerequisite. It can imply that the second action is a direct result of, or dependent on, the completion of the first action.

• Sequential Actions: It clearly states "do A, and then do B."
  • 책을 읽고서 잠이 들었다. (I read a book and then fell asleep.)
• Completion as a Prerequisite: The first action is a necessary step for the second.
  • 숙제를 다 하고서 놀러 나갔다. (I finished all my homework and then went out to play.)
• Implied Condition/Result: Sometimes, it can suggest that the second action happens because the first action was completed.
  • 그 소식을 듣고서 깜짝 놀랐다. (Having heard that news, I was very surprised.)

It is often used when the speaker wants to highlight the completion of the first action as a distinct event before moving to the next.

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Conjugation Rules

-고서 is straightforward to conjugate as it attaches directly to the verb stem without considering whether the stem ends in a vowel or a consonant.

• Verb Stem + 고서

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Knowledge Plus

• -고서 vs. -고: While often interchangeable, -고서 tends to emphasize the completion of the first action more strongly than -고. -고 can simply list actions in sequence or connect two simultaneous actions, whereas -고서 almost always implies a clear temporal separation and completion. For instance, "밥을 먹고 잠이 들었다" (I ate and fell asleep) is fine, but "밥을 먹고서 잠이 들었다" emphasizes that the eating was finished before sleeping.
• Omission of -서: In many casual conversations, the -서 part is often omitted, leaving just -고. However, when a stronger emphasis on the completion or the sequential nature is desired, -고서 is preferred.
• Past Tense Restriction: -고서 cannot be used with past tense markers (e.g., 았/었) on the first verb. The tense of the entire sentence is determined by the final verb.
  • (X) 밥을 먹었어서 잠이 들었다.
  • (O) 밥을 먹고서 잠이 들었다.
• Subject Consistency: Typically, the subject of both clauses connected by -고서 is the same. If the subjects are different, other connective endings might be more natural.