The preposition de (of) is used to express relationship and possession. If the sentence has two or more nouns, de (or d' before a vowel) is repeated before each noun: Ce sont les parents de Roger et de Luc. (They are Roger and Luke's parents./They are the parents of Roger and of Luke.)
With masculine singular and plural nouns, de contracts with the definite article le to become du or contracts with les to become des in order to express “of the”:
- Ce sont les parents du garçon. (They are the boy's parents./They are the parents of the boy.)
- Ce sont les parents des garçons. (They are the boys' parents./They are the parents of the boys.)