What is the difference between has, have and had in English grammar?
This is the most common question about english grammar.

What is the difference between has, have and had in English grammar ?
Have is all the other persons in the present tense of the verb to have.
Have is used by I, you, we, and they.
Has is the third person present tense of the verb to have.
Has is used by he, she, and it.
Had is the past tense form of to have. It is used by all subject in the past.
In the following examples you will find all forms of the verb to have, in all the tenses.
Present continuous
I am having
you are having
he / she / it is having
we are having
you are having
they are having
Past continuous
I was having
you were having
he / she / it was having
we are having
you were having
they were having
Present perfect
I have had
you have had
he / she / it has had
we are have had
you are have had
they are have had
Past perfect
I had had
you had had
he / she / it had had
we had had
you had had
they had had
Future
I will have
you will have
he / she / it will have
we will have
you will have
they will have
Future continuous
I will be having
you will be having
he / she / it will be having
we will be having
you will be having
they will be having
Future perfect
I will have had
you will have had
he / she / it will have had
we will have had
you will have had
they will have had
Present perfect continuous
I have been having
you have been having
he / she / it has been having
we have been having
you have been having
they have been having
Past perfect continuous
I had been having
you had been having
he / she / it had been having
we had been having
you had been having
they had been having
Feature perfect continuous
I will have been having
you will have been having
he / she / it will have been having
we will have been having
you will have been having
they will have been having