-기: The Plain Verb-to-Noun Ending

-기 is Korean’s plain way to turn a verb into a noun: 먹기, 주문하기, 기다리기.

You need that noun when the next word wants a thing, not a finished sentence — ordering is hard, I like speaking, we decided on going.

Forms

한국어로 말하기가 어려워요.     Speaking Korean is hard.
여기서 기다리기를 싫어해요.     I don’t like waiting here.
주문하기 전에 메뉴를 봐요.     I look at the menu before ordering.

Ending, not every word ending in 기

우리말샘 lists -기 as a nominalising ending and, separately, as a suffix that builds some nouns. Classroom focus is the ending: attach it when you productively need a noun. Do not analyse every dictionary noun in 기 as a fresh grammar move.

Vs -는 것

Both can translate as English -ing. Korean still picks one. If you need fuller clause material, lean -는 것; if you need the bare action-as-noun, -기 is often enough.

Particles still matter

• 기가 — subject (이/가): 먹기가 힘들어요
• 기를 — object (을/를): 한국어 배우기를 시작했어요
• Desire talk still often prefers -고 싶다 (-고 싶다) over calqued 기를 원하다 in beginner speech

Same unit as -을게

Ordering dialogues use -을게 / -ㄹ게 to close a promise (주문할게요) and -기 when the action itself is the noun under discussion.