Use of “have / get” something done.

This structure is known as “causative” and we use it to mean that another person does the job for us.

Example:

a. I have my hair cut once a month. (In other words, another person, “the hairdresser”, cuts my hair).
b. I have my car repaired every two months. (In other words, another person, “the mechanic”, repairs my car).

Very important:

Pay attention to the use of the verb and modal “have”, because it changes according to the tense. Let’s see some examples:

a. I have my desk cleaned every day. (present simple)
b. I had my flat painted. (past tense)
c. I am having my nails done right now. (present continuous)
d. I was having the oil in my car charged. (past continuous)
e. I have had a telephone installed. (present perfect)
f. I had had my eyes tested. (past perfect)
g. I will have my car parked. (future will)
h. I am going to have my postcards sent. (future be going to) 

• We can use the verb “get” instead of “have”. Get is more informal.

a. They got the windows replaced.
b. You got the warnings translated to your language. 

• We can also use have something done when we talk about something unpleasant that happened to us.            
                        Linda had her bag stolen yesterday.