Hi
HolaMario, of course
that can be used to refer to
plural nouns. Here is the thing.
i) When
that is used as a
relative pronoun,
that can refer to
both singular and
plural nouns. For example, both the following are correct:
Peter bought a pencil that is sharp.-
that refers to
singular pencil.
Peter bought pencils that are sharp.-
that refers to
plural pencils.
ii) When
that is used as a
demonstrative pronoun,
that can only refer
singular nouns. For example:
Following is correct:
Peter's car is more expensive than that of Jack.- '
that refers to singular
carHowever, following is incorrect:
Peter's pencils are sharper than that of Jack.- '
that is intended to refer to plural
pencils, but this is not allowed.
We can fix this sentence as:
Peter's pencils are sharper than those of Jack.p.s. Our book
EducationAisle Sentence Correction Nirvana discusses
these various avatars of “that”. Have attached the corresponding section of the book, for your reference.