Which would you say?

  1. I’m sorry that it’s you who has to tell her.

  2. I’m sorry that it’s you who have to tell her.

All of my native English speaking friends say “has”, but some ESL friends are saying this is gramatically incorrect.

In such a cleft sentence/clause, ‘it’ is just a place-holder for the clause: ‘[i] who has to tell her is you’. ‘Have’ will not work here.

– But your question is, ‘Which would you say?’ Well, I am likely to say either.