Posted by Grant Richardson, 8th August, 2015
A common grammar mistake made by students is to say things like:
Sorry I couldn’t answer your phone call. I was doing acupuncture
Assuming that the doctor was performing the procedure, you should say:
Sorry I couldn’t answer your phone call. I was having acupuncture done
The second way means that the doctor was doing the procedure to you 😎, whereas the first way means that you were doing it to yourself 😲.
The grammar you need for this sentence is called causative passive construction, or commonly referred to as “have something done“.
The general structure of this grammar is:
have + object + past participle
Notice that in the first way (I was doing acupuncture), the do changes tense:
Whereas, in the second way (I was having acupuncture done), the have changes tense:
And the object + past participle do not change
The below examples show that have changes form according to the tense, whereas object + past participle(s) (my hair cut and coloured) do not change
(except for negative haven’t had here, where we change the past participle separator and to or):
I had my hair cut and coloured two months ago.
I haven’t had my hair cut or coloured for two months.
I‘m going to have my hair cut and coloured this evening.
I‘ll be having my hair cut and coloured in two hours.
You can replace have with get for the same meaning, though, get sounds more casual than have.