Which preposition follows 'vain' when it is used as a synonym for proud?
Example:
The actress was vain ___ her looks.
It should be worth noting that I'm in ICSE, and that at this point, I don't even know if the sentence is correct at all...
I would use about in that sentence so it reads: The actress was vain about her looks , which makes complete sense as an English sentence
Just keep in mind that vain isn't perfectly synonymous with proud, as vain in that sense means to be excessively proud of or concerned about one's own appearance.
I'd say the sentence isn't quite right. My argument would be that to be vain is a state of mind, it's not an action done towards an object.
You could say "The actress was vain".
Vain means: having or showing an excessively high opinion of one's appearance - so to mention something about looks is redundant, since the word vain already refers to that.