Hello. I will really appreciate some help.

Question

Do you think it's possible to say: "She regrets not buying the house" or is it "she regrets not having bought the house", maybe both?
And one more question, please. Would you use articles in the context: "in this composition he used a number of instruments, a (piano), a (?)saxophone,an (?) acoustic and bass guitar, etc"
Thank you very much for help.

Answer 1

Both are correct -- although the first is more common.

You could use articles -- but they're not necessary -- in your second example.