Quand j'en aurai fini avec tout ça

Question

I've never really understood when to use "en" even with the lessons but with this sentence in particular, why are we using it? I know it's "finir de faire qch" but why is it needed and how do I know when to use it?

Thanks

Cécile Janty-Davies · Accepted Answer

Hi James, 
The 'en' here is part of an idiom -
en avoir fini avec quelque chose = to be done with something 
There are lots of idioms that use 'en' or 'y'.
You might know the expressions -

en avoir assez / marre = to have had enough 
s'y faire = to get used to something

Hope that helps!

Stephanie Slawek · Answer

That's strange to me. If it were "quand j'aurai fini de faire mes devoirs", then "quand j'en aurai fini" would make sense. But it's "when I'm done with all that", so there's no 'de'. Doesn't seem correct. I'm curious what the native speakers say.

Chris Wirt · Answer

Those idioms with en and y are so useful and make you sound so....French that I wonder if there couldn't be a dedicated lesson or two on them.

Blaise Pascal · Answer

Is there a dedicated page here that lists all the useful idioms that consist of en and y

Cécile Janty-Davies · Answer

Bonjour Blaise, 
I don't believe there is, but I'll suggest it to our content team.
In the meantime, you might find the following common expressions useful -
s'en aller = to go away, leave
"Je m'en vais" (I'm leaving)
s'en faire = to worry
"Ne t'en fais pas !" (Don't worry!)
en vouloir à quelqu'un - to hold a grudge against someone
"Je ne t'en veux pas" (I don't hold it against you)
en avoir marre - to be fed up
"J'en ai marre de ce bruit" (I'm fed up with this noise)
en avoir assez - to have had enough
"J'en ai assez!" (I've had enough!)
s'en sortir - to manage, get by
"Tu t'en sors?" (Are you managing?)
s'en remettre à - to rely on, leave it up to
"Je m'en remets à toi" (I'll leave it up to you)
en être - to be part of something, to be at a certain point
"Où en es-tu?" (Where are you with that?)
 
Expressions with Y
y aller - to go (there)
"On y va!" (Let's go!)
s'y connaître - to know about something, be knowledgeable
"Il s'y connaît en informatique" (He knows about computers)
s'y prendre - to go about something
"Comment t'y prends-tu?" (How do you go about it?)
y être pour quelque chose - to have something to do with it
"Je n'y suis pour rien" (I have nothing to do with it)
il y a - there is/are (also used idiomatically)
"Il n'y a pas de quoi" (You're welcome / No problem)
s'y faire - to get used to it
"Tu t'y feras" (You'll get used to it)
y compris - including
"Tout le monde, y compris toi" (Everyone, including you)
These pronouns often replace previously mentioned places (y) or things introduced by "de" (en), but in these idiomatic expressions, their meanings can be more abstract or fixed.
Hope this helps!