French language Q&A Forum

I'm wondering why it's not correct to say "me présenter à d'autres gens"?  I thought that présenter was followed by the preposition à.

Would this be incorrect: "On n'a vingt ans qu'une fois" ?

I have noticed that transparaître and derivatives are seen with both être and avoir as auxiliaries.  I assume it's because of transitive and intransitive verb usage. Is this the reason ? Can you please give me some examples. 

Why it says "docteur ès sciences mathématiques" rather than "docteur en sciences mathématiques"? Does it have different meaning?

  I found this on the Lawless French website.   Which is correct?

What is the exact difference between Imparfait and Plus que parfait (PQP). Some people say for 'had', we have to used PQP but some people say that for 'had', even imparfait can be used, but exactly in which situations we have to use imparfait and PQP, nobody is able to explain logically. Anybody, reply please...

Are there any fixed verbs for pronominal, or any verb can be a pronominal verb ? Somebody, reply please.

Merci en avance !

Are any of these alternative answers possible?

1. Je me souviens toujours de la première fois ... (In place of encore - I often have trouble with encore and toujours in this context of still, but in some cases I believe they can both be equally correct?)

2. Elle a passé la plupart de sa carrière ... (in place of la majorité or l’essentiel)

3. ... dont elle a souffert pendant toute sa vie (in place of ... don’t elle a souffert tout au long de sa vie)

Thanks