pronombres relativos who,which, that, what

Reflexion!...
Refiriendose a personas se emplea WHO; a animales cosas WHICH; a personas, animales o cosas THAT; a cosas WHAT.

A WHO corresponde whom y whose   (personas)

A WHICH corresponde which y whose (animales)

A WHICH corresponde which, to which y of wich (cosas)

Ejemplos:

The man who came/El hombre que vino

The cat which she gave you/El gato que ella te dió

The rose which he gave you/La rosa que él te dió

The book that I gave you/El libro que te dí