There's an idiomatic expression "to be done with something" meaning to finish it. And there's a sentence in a question posted here:
When the sun dropped low behind the hills and we were done playing for the day, ...
It is a correct sentence, and to me, it's perfectly understandable, but...
There's not "with" after "we were done", and it puzzled me.
I have never met it as it is in the sentence - without with, and I'm wondering why it is missing there.
Is it the gerund "playing" that makes "with" unnecessary, or anything else?
Are there other expressions like "be done" where the use of the gerund excludes the use of a preposition before it or allows omitting a preposition? Could you provide a few examples of those?