What is the difference between 〜してんじゃねえ and するんじゃねえ?


>
> 「糧食、エナジーパック、弾薬、修理部品は所定数を確保済み。ああ、どっかの馬鹿戦隊長のために、足回りの修理部品は多目に用意しといたぜ。おめぇ、簡単な修理は出来るんだよな」
>
> 「ええ。よく壊すので」
>
> 「しれっと **返してんじゃねえよ** このクソガキ。……持ってけるのは一機だけだ。同じ調子で戦う **んじゃねえぞ** 」

86─エイティシックス─ 安里アサト

I notice that both 〜してんじゃねえ and ～するんじゃねえ can mean "Don’t do…". So is there any
difference between the two expressions?




～してんじゃねえ is short for ～し **ている** んじゃねえ (see
[this](https://japanese.stackexchange.com/a/61959/5010)), so する is in the
progressive/perfective (-teiru) form. Thus this only refers to what's already
going on or what just happened.

On the other hand, ～するんじゃねえ does not have the progressive -teiru. It can refer
to both what's going on now and what's going to happen in the future.

  * 泣いてんじゃねえ。  
Hey, don't cry. / Stop crying.  
(said to someone crying now)

  * 泣くんじゃねえ。  
Hey, don't cry.  
(said either to someone crying now or to someone who may cry in the future)

In the context in question, しれっと返してんじゃねえ and しれっと返すんじゃねえ are interchangeable.
戦うんじゃねえ is not interchangeable with 戦ってんじゃねえ because the battle is not in
progress now.




～してんじゃねえ is short for ～し **ている** んじゃねえ (see
[this](https://japanese.stackexchange.com/a/61959/5010)), so する is in the
progressive/perfective (-teiru) form. Thus this only refers to what's already
going on or what just happened.

On the other hand, ～するんじゃねえ does not have the progressive -teiru. It can refer
to both what's going on now and what's going to happen in the future.

  * 泣いてんじゃねえ。  
Hey, don't cry. / Stop crying.  
(said to someone crying now)

  * 泣くんじゃねえ。  
Hey, don't cry.  
(said either to someone crying now or to someone who may cry in the future)

In the context in question, しれっと返してんじゃねえ and しれっと返すんじゃねえ are interchangeable.
戦うんじゃねえ is not interchangeable with 戦ってんじゃねえ because the battle is not in
progress now.

