A friend of mine / a friend of Tom’s, etc.
We say “a friend of mine/yours/his/hers/ours/theirs”:
– I’m going to a wedding on Saturday. A friend of mine is getting married. (not a friend of me)
– We took a trip with some friends of ours. (not some friends of us)
– Michael had an argument with a neighbor of his.
– It was a good idea of yours to go to the movies.
In the same way we say “a friend of my sister’s / (a friend) of Tom’s,” etc.:
– That woman over there is a friend of my sister’s.
– It was a goog idea of Tom’s to go to the movies.
My own … / your own …, etc.
We use my/your/his/her/its/our/their before own:
my own house your own car her own room (not an own house, an own car, etc.)
My own … / your own …, etc. = something that is only mine/yours, etc., not shared or borrowed:
– I don’t want to share a room with anybody. I want my own room.
– Vicky and George would like to have their own house.
– It’s a shame that the apartment doesn’t have its own parking space.
– It’s my own fault that I don’t have any money. I buy too many things I don’t need.
– Why do you want to borrow my car? Why don’t you use your own? (= your own car)
You can also use own to say that you do something yourself instead of somebody else doing it for you.
– Bill usually cuts his own hair. (= he cuts it himself; he doesn’t go to a barber)
– I’d like to have a garden so that I could grow my own vegetables. (= grow them myself instead of buying them in stores)
On my own / on your own, etc. = independently.
- My children are living on their own. (= living in their own place and supporting themselves)
- I traveled around Japan on my own. (= not on an organized tour)
- Are you raising your children on your own? (= without the other parent)
By myself / by yourself, etc.
By myself / by yourself / by themselves, etc. = alone, without other people:
- I like living by myself.
- “Did you go to Hawaii by yourself?” “No, with a friend.”
- Jack was sitting by himself in a corner of the cafe.
- Student drivers are not allowed to drive by themselves.