EXPLANATION OF CAUSATIVE HAVE/ GET

CAUSATIVE HAVE/ GET (HAVE/ GET SOMETHING DONE)

USE

1. We use the structure have/get something done when we want to say that  someone else  does something for us.
Compare the sentences:
I fixed the washing machine. (I did it myself)
I had my washing machine fixed. (I asked someone to fix it for me)

FORM

Tense	have/get something done
Present Simple	I have/get my hair cut.
Past Simple	I had/got my hair cut.
Present Continuous	I'm having/getting my hair cut.
Past Continuous	I was having/getting my hair cut.
Present Perfect	I have had my hair cut.
Past Perfect	I had had my hair cut.
will	I will have/ get my hair cut.
must	I must have/ get my hair cut.
be going to	I'm going to have/ get my hair cut.