in general when you have the structure:
conjugation of être followed by an infinitive you need to use:
conjugation of être + de + infinitive (when the infinitive isn't acting as a passive infinitive)
conjugation of être + à + infinitive (when the infinitive is acting as a passive infinitive)
A test that seems to work to determine if the infinitive conveys a passive meaning is as follows:
if the English translation to be + past participle of verb makes sense then the infinitive conveys a passive sense
Ce dossier est à vérifier. – This file needs verifying
cette voiture est à vendre – This car is for sale
il est à souhaiter que - it is to be hoped that
toutes ces fenêtres sont à péparer - All these windows are to be repaired
Mon rêve est de devenir médecin – my dream is to become a doctor
son objectif est de renvoyer le President – Her aim is to sack the President.
Can you explain this further: "if the English translation to be + past participle of verb makes sense then the infinitive conveys a passive sense."? Can you give an example in French? I'm really having a tough time understanding when to use a or de. Thank you ahead of time for your help!
I am not sure if you are having problems with determining when to use the prepositions à or de before an infinitive or with the specific concept of passive infinitives. Let's start with the passive infinitive.
In English, the passive infinitive is formed using the constructs:
• to be + past participle
• be + past participle (typically after auxiliary verbs such as may, could, should, etc. )
The police are determined to catch the murderer. (active infinitive)
The police are confident that the murderer will be caught soon. (passive infinitive)
Let me help you. (active infinitive)
She doesn’t want to be helped. (passive infinitive)
She plans to invite them (active infinitive)
I am afraid to make mistakes (active infinitive)
They expect to be invited (passive infinitive)
We waited to be given instructions (passive infinitive)
She hopes to be elected. (passive infinitive)
These doors should be shut at night. (passive infinitive)
Now for the French equivalent (copied from section 428 of the book A Comprehensive French Grammar by Glanville Price)
After verbs such as être, y avoir, rester when English uses a passive infinitive to express a possible, desirable or necessary course of action, French uses à + infinitive
toutes ces fenêtres sont à péparer All these windows are to be repaired
in n’y a rien à faire There is nothing to be done
cela reste à decider That remains to be decided
In such sentences the grammatical subject is, according to the sense, the object of the infinitive. In other words the examples express:
one needs to repair these windows
one can do nothing
one has still to decide that
Ce dossier est à vérifier. This file needs verifying
cette voiture est à vendre This car is for sale
Mon rêve est de devenir médecin my dream is to become a doctor
son objectif est de renvoyer le President Her aim is to sack the President.
je suis de retour I am back
Thank you for this. I think I'm going to try to remember when to use "a" or "de" this way : If the subject isn't taking action for the verb -- Your example above: Ce dossier est a verifier. "Ce dossier" is not doing the verifying. Thus, use "a" before the infinitive.
If, on the other hand the subject IS taking action--"Mon reve est de devinir medecin -- "Mon reve" or roughly, me, wants to become a doctor.
I also saw somewhere that "de" is used in situations of obligation or feelings. "A" is more In situations reflecting attitude, function, ability or purpose.
The 'de' is because a lot of times you need a random 'de' or 'a' before a verb when you would think that the english 'to' would be implied by the verb itself, though I couldn't explain and don't know if there is a rule as to when you need to use 'de' vs 'a' vs no preposition at all.
Do not use a preposition if the infinitive if the verb follows a verb such as 'pouvoir' or 'vouloir' (just examples), otherwise use 'à' or 'de.' 'De' will be used n an impersonal (il = it or something similar), otherwise use 'à.' ex: Je veux courir, mon desir est à courir, il n'est pas enneyeux de courir)
Some lists of verbs+prepositions can be found here: http://french.about.com/library/prepositions/bl_prep_verbs.htm
I screwed up this exercise, but upon reflection, I think it's because of the "ne ... plus" construction. "Ne tuer plus" is "not to kill anymore" but the words get rearranged because it's an infinitive form that acts as... well, the object of "my desire." :P
EDIT: Wait, that didn't answer your question at all! I went astray from my original thinking. "Plus de" sort of means "more of" so that's what I think is being rearranged!
I think it's getting a bit far from the original. Not just the "for", but the "no more killing". That translation leaves the question of who is doing the killing quite unaddressed, whereas the French sentence clearly shows that it is the speaker who wishes not to kill any more. Quite different, really.