Articles & il y a

Three things to internalise. One: every noun in French has a GENDER (masculine or feminine) and the indefinite article shows it: un livre (m.), une trousse (f.), des stylos (plural). The plural des is the same regardless of gender. Two: il y a means "there is / there are" — frozen, never conjugated, used for both singular and plural. Il y a un livre (singular) / il y a des livres (plural). Three: under negation, the indefinite articles collapse to de/d', exactly like the partitive (which you'll meet in the next skill). Il y a un livre → il n'y a pas DE livre. The exception: after être, articles DON'T collapse — c'est UN livre stays ce n'est pas UN livre.