odyssey wrote:I'm sorry that it's you that has to tell her.
Every time. Singular or plural.
Except when the relative pronoun (
who or
that) is a plural subject pronoun and relates to a plural subject.
Thus, in addressing a crowd:
I'm sorry that it's you that
have to tell her.
[
that being the subject, and not
you]
BTW,
that is incorrect in your example, and should be
who...
Murphy (1990); Eastwood (1992)