A couple things I dont understand...

Question

Et les au-revoirs qui n'en finissent jamais au téléphone - Why is 'EN' used here?

je ferai gagner du temps à tout le monde - What's the expression here? Because I don't understand why "À" is used here?

Accepted Answer

Hi James,
1. The verb -
n'en pas finir =   to drag on 
has the idiomatic 'en' in its infinitive just like 's'en aller' does.
Ce film n'en finit pas = This film is never-ending 
2. The verb -
faire gagner du temps à quelqu'un = to save somebody some time
En m'aidant à préparer les légumes, elle m'a fait gagner du temps = By helping to prepare the veg, she helped me save some time.
Hope this helps!

Answer

Why the en in French? It's great French to have it, but I think it would be also possible without en.faire gagner à qqn -- to get someone to win, wo make someone win