Why do we use "après que" instead of "après" if there is no subjunctive verb to follow?

Question

Hi,
What is the difference between these two sentences?
Elles rentrent après que le bus les a déposées.
Elles rentrent après le bus les a déposées.
I don't understand why the second one is not correct so I guess I don't understand when to use "après que" vs a simple "après." Don't they mean the same thing?  Is there a rule?  Thanks.

Accepted Answer

There are three cases to distinguish:
1) après + noun Après le dîner nous sommes partis.
2) après + verb in the infinitiveAprès avoir dîné nous sommes partis.
3) après + que + clauseNous dînerons après que le film sera terminé.
I hope this helps,
-- Chris (not a native speaker).

Answer

Bonjour John !The difference is that the sentence with only "après" is incorrect in French :)As Chris pointed out, you can only use "après" + noun or a verb in the past infinitive (avoir fait, avoir mangé...).When you have a clause with a conjugated verb afterwards, it becomes a subordinate clause introduced by the set adverbial phrase "après que".Other similar phrases include: maintenant que, depuis que, une fois que. None of them are followed by Le Subjonctif.
Indeed, "que" is not necessarily associated with Le Subjonctif, as the use of this mood is determined by the presence of a doubt. With "après que", the action has already happened *for sure*, hence the use of L'Indicatif instead.See also : https://french.kwiziq.com/revision/glossary/mood/the-french-subjunctive-mood-le-mode-subjonctif-ou-le-subjonctif
I hope that's helpful!Bonne journée !

Answer

Thanks Chris and Aurélie. That summary is very helpful. It's just what I needed. 
Bonne journée.