French language Q&A Forum

This isn't covered in fully in the lessons, but I would like to know: how do we know when to use à + verb as opposed to de + verb? Some lessons cover de + verb, for example to say 'before running' I can say 'avant de courir'. But I'm not sure about the other case, à + verb. Any answers? I haven't had much luck searching the web for this, so any help would be much appreciated.

This is the one specific to this exercise:

"qui consiste à appliquer de la peinture sur de l'eau". Why not "qui consiste d'appliquer ...?"

Here are other cases I've found on this website:

nous avons commencé à le faire il y a quelques années

quand tu auras fini de ranger ta chambre, tu m'aideras à faire la vaisselle.

on est toujours pressé d'oublier les moments délicats

le temps que je finisse de manger, ... j'aurai fini de vérifier ... le temps que ça lui prend de se préparer

Is it arreter (not s'arreter) because "ce que je faisais" is the object and s'arreter as a reflexive can't have an object??  

And unlike 'the rest of the day' (journee), I felt better 'in the evening' is not obviously 'duration' so why soiree not soir, especially when this morning is matin?

Why faire (bien) DE venir when faire doesn't have to take a preposition and A is the normal connector in those circumstances?

Is there any rule at all to determine relaxer vs se relaxer vs detendre vs se detendre?

And on and on it goes ...

When do I use j'ai or je suis because they both mean the same thing so I don't know when's the time to use which I have

Is this speed of talking really normal? Is this a good way of testing listening skills at B1 level.

Pourquoi est-ce que la ponctuation ne fait-elle pas partie de la dictée?

Why is it « nouvel » and not « neuf » when the raincoat would be brand new from the store? I thought neuf is for new, never been used, and nouvel is for been used but still pretty new.