Pronouns y en

Y swallows à plus a thing or a place; en swallows de plus a thing, along with every partitive and quantity. Match the pronoun to the preposition the verb takes: penser à gives j'y pense, parler de gives j'en parle. Neither works for a person, where you need je pense à lui.

Y replaces à plus a thing or a place, and goes before the verb: je vais à la banque becomes j'y vais, je pense à mon travail becomes j'y pense. It is not for people: je pense à ma sœur becomes je pense à elle.

With a number or a quantity, French keeps the number at the end and needs en for the thing counted: j'en ai trois, il en achète beaucoup. English can say I have three; French cannot drop the en. The everyday version is il y en a, there is some.

In a positive command, y and en follow the verb with a hyphen, and an -er tu command gets its s back, said as a z: va becomes vas-y, mange becomes manges-en. In a negative command the pronoun goes back in front and the s goes again: n'y va pas.