Translation:The child sleeps.
Why do you sometimes us "잡니다" alone, while other times it has to be "잠을 잡니다" or "잠잡니다"??
'을' is an object particle. Its used when defining an object to a verb. Thus, to answer your question, the use between '잠을잡니다...' and '잠잡니다...' depends on the sentence's context. Either way, both can be correct.
I'm not Korean, but I asked my teacher about the difference between 자다 and 잠자다. 잠자다 is a shortened version of 잠을 자다, which literally means "to sleep a sleep". So 자다 and 잠자다 are basically the same, except 잠자다 has more emphasis and sounds more specific
아이 is an singular of child.. You have to put 들 after subject to form a plural.. More than 1 child = children = 아이들
I think 자다 is the dictionary form of the verb. I do not believe it is used in conversation as it has to be conjugated b4 use. Seems like most Korean verbs end with 다. Koreans speakers, please correct my explanation.
is it possible to drop 잠 here ? like when you say sleep tight it's 잘 자.. not 잘 잠자
I think because 는 is a topic particle and serves to put some emphasis on the child ...
I think because 는 is a topic participle and serves to put some emphasis on ''the child''
From my understanding both are correct and can be used interchangeably, but 는 is more often used when comparing subject with something else in context. If you were just talking about a child, 아이가 works, but if another child was previously mentioned you would use 아이는 because you'd be comparing it to a previously mentioned child. It is a subtle difference, there are videos about it on YouTube.