"오후에 구름이 끼기 시작했어요."

Translation: It started getting cloudy in the afternoon.

[LiKenun]

구름: cloud

끼다: to cloud over

[LesChristiansen]

구름이 끼기 literally means to put clouds on. This looks like another idiom to learn.

[seouldasein]

"To get" is also a good translation here. It started to get cloudy is the same as it started getting cloudy.

[Lorenzo410951]

Verb stem+기 시작하다:start to...

[mm]

I thought it meant "gather", like clouds gathering

[angiebordoli]

Can someone explain the function of the particle 기 here please

[ammaaya]

-기 is a particle that gets added to verbs to convert them into nouns. You can think of it similar to -ing in English or -ando/endo in Spanish

A lot of words/grammar principles require nouns in front on them, so 기 is used a lot.
You'll see it a lot in V기 때문(에) = because of V기,
or in V기 시작하다 = To start doing V기

Also if you use any computer/Internet stuff in Korean language, then you'll see a lot of buttons with Verb+기 written on them, which tell you what the button does. It's very common.

[mcguirepatr]

Great comments!