HAVE + something + PAST PARTICIPLE
Someone does something for you
She has her hair cut every month
She is having her hair cut now
I had my hair cut yesterday
I was having my hair cut yesterday at 5pm
I will have my hair cut tomorrow
I am going to have my hair cut at 6pm
By the time he arrived, I had had my hair cut
I have just had my hair cut
You should have your hair cut. It is too long.
OTHER EXPRESSIONS: have (my, your,...) nails polished, have one's legs waxed,
have my car repaired,...