"남자아이는 키가 큽니다."
Translation:The boy is tall.
It’s interesting that 키 (height) and 크다 (to be big) are used in the same sentence here.
키 come from Middle Korean 킈 which in turn comes from 크+의.
Saying this sentence more literally: the boy… bigness is big.
For describing people's height, it's common to say, literally, "the size is big." 키가 is size.
Whoops, excuse me, 키 is height you're right. 크기 is size. I confused them :/
Your slight mistake followed by a correction provides me more info than just the correct answer
Makes sense now. So the sentence is saying that the boy's hieght is big, thus, the correct translation should be - tall. Arraso!
The boy is big can imply that the boy is fat, which is not really conveyed by this sentence.