The causative is a common structure in English. It is used when one thing or person causes another thing or person to do something. Under this structure, I don’t understand where to use “get” or “have”. For example:
I will get the tires replaced tomorrow.
I will have the oil changed tomorrow.
Please tell me the basic differene between using “get” and “have”. As my teacher says if I use “have” (causative) in the first sentence in stead of “get”, it is grammatically wrong.
I would really appreciate your input, please help me.
Both are correct, however, ‘get’ is more informal than ‘have’. I’ll give you some more examples.
You should have/ get the job done professionally.
I had/got the machine repaired only last week.
Where did you have/ get your hair cut?
We’re having/ getting a new kitchen fitted.
Your sentences are quite correct, but they can be replace them as follows:
I will have my tires replaced tomorrow.
I will have the oil replaced tomorrow.
They could also be replaced by the present continuous, on condition that you have arranged for all this to happen tomorrow or that you intend to have this done tomorrow:
I’m having/ getting my tires replaced tomorrow.
I’m having/ getting my oil replaced tomorrow.
This pattern means ’ to cause something to be done.’
There’s another pattern: ‘to cause someone to do something’
EX.: I’ll have the garage replace my tires/ my oil tomorrow.
EX.: I’ll get the garage to replace my tires/ my oil tomorrow.
EX.: I had the garage replace my tires/ my oil tomorrow.
Ex.: I got the garage to replace my tires/ my oil tomorrow.
So to give an answer to your question/ Your teacher is partly wrong. ‘have’ and ‘get’ can both be used for the causative form, only ‘get’ is less formal. As I’ve already said: ‘have’ and ‘get’ are both correct. However, I would use ‘have’ instead of ‘get’.