Student or Learner
It is you who has/have eaten all the food.
Should I use 'has' or 'have'?
Thanks in advance.
There are no circumstances under which it would ever be grammatical to say
*you who has
any more than there would ever be to say
The pronoun 'you', irrespective of the number of people to whom it refers, takes one, and only one, verb form in the present tense, to wit the uninflected base form of the verb. Thus
It is you who have...
is the only possibility.
It is Henry who has eaten the food.
It is those two boys who have eaten the food.
It is you (singular) who has eaten the food.
It is you (plural) who have eaten the food.
Or so it seems to me.
I agree with singular 'has'.
I would instinctively say: It's you that's eaten all the food! Certainly not: It's you that've eaten all the food. So, I guess the same applies if you use 'who' rather than 'that'.
[Note, I'm making no claims to grammatical correctness here. But that's normal AusE.]
who = you --> have
Philo, our master, is dead right.