Breakdown of Du darfst dich nicht einmischen in den Streit!
du
you (informal singular)
in
in
nicht
not
dürfen
to be allowed to, may
Questions & Answers about Du darfst dich nicht einmischen in den Streit!
Why is in den Streit at the very end of the sentence, after the infinitive einmischen?
This is an example of using the Nachfeld (the "after-field"). Normally, a prepositional phrase like in den Streit would go in the middle of the sentence, right before the final verb (Du darfst dich nicht in den Streit einmischen!). Moving heavy or important phrases to the very end, past the final verb, is common in spoken German to emphasize them or to tack them on as an afterthought.
Is einmischen a separable verb, and if so, why isn't the prefix separated here?
Yes, einmischen is a separable verb. However, because the modal verb darfst occupies the second position in the sentence, the main verb is pushed to the end of the clause in its full infinitive form (einmischen). The only reason it isn't the absolute last word in the sentence is because the phrase in den Streit was pushed into the Nachfeld.
Why does the preposition in take the accusative case (den Streit) in this sentence?
The reflexive verb sich einmischen (to interfere/meddle) requires the preposition in plus the accusative case. Even though an argument is an abstract concept, you can think of it as a directed action: you are inserting yourself into a situation. This idea of movement or direction triggers the accusative with the two-way preposition in.
Why is darfst ... nicht translated as "must not" instead of "do not have to"?