Look at the illustration below.
From the illustration, we can write a story line as following:
1. Bob’s computer is broken.
2. He takes it to the repairman.
3. He has the repairman fix his computer OR He has his computer fixed.
From the story line above, we can see that Bob DOES NOT fix his computer by himself. He ASKS SOMEONE ELSE to do it. This kind of sentence is called CAUSATIVE.
CAUSATIVE is a sentence indicates someone asks, tells, or makes someone else to do something for him/her.
There are TWO kinds of CAUSATIVE: ACTIVE and PASSIVE.
From the example he has the repairman fix his computer, we can draw a formula of ACTIVE CAUSATIVE:
The Object (active) is usually the person whom the subject tells to do something for him/her, while the Object (passive) is something that the subject tells someone else to do.
From the example he has the repairman fix his computer, the Object (active) is the repairman, while the Object (passive) is his computer.
NOTE: We can also use get/got for ACTIVE CAUSATIVE, but we MUST ADD to infinitive AFTER THE VERB get/got. E.g. He gets the repairman to fix his computer.
From the example he has his computer fixed, we can draw a formula of PASSIVE CAUSATIVE:
PS: Sorry for the terrible drawing, I’m not a drawer. Not to mention, I drew it using the program paint, so it got terrible 😀