Look at what the pronoun replaces and the construction it belongs to. En often relates to de or a quantity; y often relates to a place or an à complement. These are starting patterns, not rules based only on the English translation.

Useful contrasts

Original With a pronoun What to notice
Tu veux du café ? Oui, j'en veux. A partitive quantity.
J'ai trois livres. J'en ai trois. The number stays.
J'ai besoin de ce document. J'en ai besoin. The construction is avoir besoin de.
Je vais à Lyon. J'y vais. Destination/place.
Je reviens de Lyon. J'en reviens. Origin with de, not automatically y for every place.
Je pense à ce problème. J'y pense. A thing introduced by à in this construction.

Other complements need other pronouns. Je regarde le film → je le regarde is not an en/y choice. Learn the verb's construction as well as its meaning.

People do not create a blanket ban

Des amis ? J'en ai deux uses en with people in a quantity expression. With an identified person, the appropriate form also depends on the verb: je pense à Léa → je pense à elle, but je parle à Léa → je lui parle. Do not replace every à + person phrase with à lui/à elle.

Stressed forms such as de lui or d'elle can make a person's identity explicit. They do not establish that en is impossible whenever a human referent is involved. For an unfamiliar construction, check a complete example rather than a three-step universal decision tree.

Placement follows the construction

  • Ordinary finite clause: j'en veux, j'y pense.
  • Compound tense: j'en ai pris, before the auxiliary.
  • Infinitive governed by another verb: je vais en prendre, je veux y aller, before the infinitive they belong to.
  • Affirmative imperative: prends-en, vas-y, attached after that verb.
  • Negative imperative: n'en prends pas, n'y va pas, before the verb again.

These cover the examples here, not every causative or multi-verb construction. The pronoun-order guide distinguishes ordinary preverbal order from affirmative commands.

In il y en a trois, y precedes en. Do not equate the informal contractions of il y a and il y en a: removing en can change the construction and meaning.

Check your choice

  1. Je reviens de Paris → J'___ reviens.
  2. J'ai deux amis ici → J'___ ai deux ici.
  3. Je veux aller à Lyon → Je veux ___ aller.
  4. Give the negative command corresponding to prends-en.

Answers: en; en; y; n'en prends pas. Explain what is replaced and which verb governs it. Practise in a sentence or exchange; using these pronouns does not by itself certify fluency.