Questions & Answers about Bitte ruf mich vorher an, wenn du kommst.
Because the verb is anrufen, which is a separable verb.
In many German sentences, separable verbs split into:
- the main verb part in its normal position
- the prefix at the end
So:
- infinitive: anrufen
- imperative here: ruf ... an
That is why the sentence says:
- Ruf mich an. = Call me.
and not anruf mich.
Again, this happens because anrufen is separable.
In a main clause, the prefix an- moves to the end:
- Ich rufe dich an.
- Ruf mich an.
But when the verb stays in the infinitive, it does not split:
- Ich will dich anrufen.
- Kannst du mich anrufen?
So in Bitte ruf mich vorher an, an is at the end because this is a main clause with a conjugated separable verb.