Core Pattern Rule: -기 전에 (Before doing)
This pattern is used to indicate that one action takes place before another. It attaches to a verb stem to create a clause that means "before doing [verb]".
Formation
It's very simple: attach -기 전에 directly to the verb stem, regardless of whether it ends in a vowel or a consonant.
가다 (to go): 가 + 기 전에 → 가기 전에 (before going)
먹다 (to eat): 먹 + 기 전에 → 먹기 전에 (before eating)
만들다 (to make): 만들 + 기 전에 → 만들기 전에 (before making)
Usage
The clause with -기 전에 sets the time reference. The main clause contains the action that must happen first.
Sentence Structure: [Action to do first] + [Action to do second]-기 전에.
Example: 밥 먹기 전에 손 씻어. (Wash your hands before eating.)
Action 1: Wash your hands.
Action 2: Eat.
Tense
The -기 전에 clause itself doesn't get conjugated for tense. The tense of the entire sentence is shown on the final verb.
Past Tense: 말하기 전에 생각했어요? (Did you think before you spoke?) - The thinking happened before the speaking, both in the past.
가기 전에 전화해. / 밥 먹기 전에 손 씻어. / 시작하기 전에 화장실 다녀와.
Native Nuance: A Sense of Urgency
While -기 전에 literally means "before," it often carries an important nuance of advice, warning, or urgency. It's not just a neutral time marker; it frequently implies "...before it's too late" or "...while you still can."
Giving Advice or Warnings
Many of the examples are commands that advise someone to act promptly to avoid a negative outcome.
후회하기 전에 잘해. (Treat them well before you regret it.)
잊어버리기 전에 메모해. (Take a note before you forget.)
Expressing a Deadline
It can also be used to state a necessary condition before a certain point in time.
늦기 전에 취소해. (Cancel before it's too late.)