After eating - après avoir mangé - why is this wrong?

Question

The sentence for translation was: "help clearing the table after eating."  I wrote "après avoir mangé" for "after eating" and this was marked wrong.  They wanted "après manger".  Can anyone help me understand why "après avoir mangé"   is wrong?

Accepted Answer

Mary, I suspect this is a matter of 
1. the specificity of the translation, 
2. the usual usage in French in a general directive such as this. 
Après avoir mangé - after having eaten. Après manger - after eating.

Answer

The normal way of saying either "after having done" or "after doing" is "après avoir fait" as explained here:

Après avoir fait = After doing in French (auxiliary avoir)

But in the specific case of eating, there is a fixed expression "après manger" which can be used instead, and is, perhaps, more idiomatic. I don't think "après avoir mangé" is wrong, however.

There is a similar expression "après boire", but, in general, you can't use a present infinitive after après.

https://forum.wordreference.com/threads/apr%C3%A8s-manger-boire-apr%C3%A8s-infinitif.1009468/