come in here这句话在电影里看到，不是说副词前不用介词吗？here是副词

come in 和 here 分开看 come in 当成一个词 进来 就容易理解了
再比如说 come on in come on 表示鼓励 come in 意思是进来 整个意思就是 你快进来吧 有鼓励的意思在里面 你不能说 on 怎么和 in 搭配了呢 有一些都是语言习惯 如果不是考试的话不用纠结于语法

我赞成语法不是处怎麼都谨慎的。
come here 可以。

entrance = come in here入口

You ask us to find a guy, and you come traipsing in here with a guy of your own?什么

Do not ler her come in here under any circumstance无论如何别叫她进来

You can't come in here!不行！你不能进来

Come on,get in here!老弟

Sometimes I come in here just to get away from it.有时我会进进出出的玩

Becky, do not let her come in here under any circumstances. Becky不管怎么样都不能让她进来

I'm sorry. I don't come in here a lot.对不起

Excuse me,sir? Hi. You come in here all the time.打扰一下

Cool. But why would a cop come in here? They don't serve doughnuts.真酷

所以并没有错，理解不同吧，要具体理解的。

这些是地道的说法，介词短语做副词修饰副词，口语中常说的是come here！