11.4Cuyo (adj.)
Cuyo corresponds to English ‘whose’, ‘of which’:
el chico cuyo libro pedí prestado
the boy whose book I asked to borrow
el atentado, cuyo motivo desconocemos todavía
the outrage, the motive for which we still do not know
la niña a cuyo lado dormía un cachorrito
the girl at whose side a little puppy was sleeping
Cuyo agrees with the noun following it, not with its antecedent noun:
la empresa cuyos productos comprábamos
the firm whose products we used to buy
Cuyo (adj.) 11.4