laisser, voir and entendre + Infinitive

The faire causatif page dealt with a verb that takes a bare infinitive and behaves like a grammatical operator. It is not alone. A handful of other verbs do the same, and they cluster around one idea: witnessing an action, or not preventing it.

• voir, regarder - see, watch
• entendre, écouter - hear, listen to
• sentir - feel, smell
• laisser - let, allow

Every one of them takes an infinitive with no preposition. That much English speakers get right without thinking, because English agrees: "I saw him leave", not "I saw him to leave". The difficulty is in the wiring around it.

The bare infinitive, and why it is worth naming

The infinitive or subjunctive page sorted French triggers into three columns: bare infinitive, de plus infinitive, à plus infinitive. These verbs sit firmly in the first column, alongside vouloir, pouvoir, devoir, savoir, aller and faire.

• Je le vois venir. (I see him coming.)
• Je l'entends chanter. (I hear her singing.)
• Elle nous regarde jouer. (She is watching us play.)
• Je sens venir le froid. (I can feel the cold coming.)
• Laisse-moi partir. (Let me go.)

Not je le vois de venir, not laisse-moi à partir. Nothing at all.

Two side notes while we are here. French has no separate present participle in this construction: "I hear her singing" is je l'entends chanter, with an infinitive, and je l'entends chantant is not French. And voir, entendre and sentir often correspond to English "can see, can hear, can feel" with no extra verb: je l'entends is "I can hear her".

Where a noun object goes

With a noun rather than a pronoun, French allows the object on either side of the infinitive, and the preference depends on how heavy the sentence is.

• On entend chanter les oiseaux. / On entend les oiseaux chanter. (You can hear the birds singing.)
• J'ai vu partir Marie. / J'ai vu Marie partir. (I saw Marie leave.)

Both are correct. Where the infinitive has no object of its own, French tends to put the noun after it, which keeps the two verbs together: on entend chanter les oiseaux is the more idiomatic of the pair.

Where the infinitive does have its own object, that freedom disappears, because two nouns after the infinitive would be unreadable. The witnessed person goes first:

• J'ai vu Marie fermer la porte. (I saw Marie close the door.)
• Not j'ai vu fermer la porte Marie.

Where a pronoun goes: no choice at all

A pronoun object has one home, and it is in front of the conjugated verb.

• Je le vois venir. (I see him coming.) - never je vois le venir.
• Je les entends chanter. (I can hear them singing.)
• Je les ai entendus chanter. (I heard them singing.) - compound tense, so in front of the auxiliary.
• Laisse-le partir. (Let him go.) - positive imperative, so the pronoun follows, as always.

This is the same rule as the causative, and for the same reason: the two verbs are read as a block.

The agreement test, and how it differs from faire

Now the interesting part, and the place where these verbs are not like faire. The participles vu, entendu, regardé, laissé can agree with a preceding direct object. Whether they do depends on a single question:

Is the thing in front of the participle doing the infinitive's action, or having it done to it?

Doing it: agree.

• Je les ai vus partir. (I saw them leave.) - they left, so vus.
• La chanteuse que j'ai entendue chanter. (The singer I heard sing.) - she sang, so entendue.
• Je l'ai vue tomber. (I saw her fall.)

Having it done to it: no agreement.

• La chanson que j'ai entendu chanter. (The song I heard sung.) - the song did not sing, so entendu, plain.
• La pièce que j'ai vu jouer. (The play I saw performed.)
• Les arbres qu'il a laissé couper. (The trees he let be cut down.)

Compare with the causative, where the question never arises: fait plus an infinitive is invariable in every case, no test required. So la voiture que j'ai fait réparer has no e, while la femme que j'ai vue partir does.

A frank note on laissé: modern usage increasingly leaves it invariable in all positions, and the spelling reform of 1990 blessed that. Je les ai laissé partir is now widely accepted alongside laissés. Examiners tend to accept both; the perception verbs proper are the ones where the test still bites.

laisser versus permettre

Two verbs, one English word, and different plumbing.

• Je le laisse partir. (I let him go.)
• Je lui permets de partir. (I allow him to leave.)
• Je lui laisse partir and je le permets partir are both wrong.

permettre belongs to the à quelqu'un de faire family covered on the infinitive or subjunctive page; laisser does not. In register, laisser is the ordinary word and often means "not stop" rather than "give permission": laisse-le dormir is closer to "leave him to sleep" than to any granting of rights.

laisser faire and laisser tomber

Two set expressions, both built from laisser plus an infinitive, and neither of them meaning what the parts say.

laisser faire = to let it be, to not interfere.

• Laisse faire, ça va s'arranger. (Leave it, it will sort itself out.)
• As a noun, le laisser-faire, which English borrowed whole for the economic doctrine.

laisser tomber = to drop. Start with the literal sense and the figurative one follows.

• Il a laissé tomber son verre. (He dropped his glass.) - literal.
• Elle a laissé tomber ses études. (She gave up her studies.) - figurative, and much commoner.
• Il m'a laissé tomber. (He let me down.)
• Laisse tomber. (Forget it. / Never mind.) - the everyday one, used constantly.

Laisse tomber on its own is worth having ready-made. It is what a French speaker says when a conversation is not worth continuing, and it is far more idiomatic than any of the textbook alternatives.

Worked examples

• Je le vois venir. (I see him coming. / I can see what he is up to.) - literal and figurative both live in this phrase.
• On entend chanter les oiseaux. (You can hear the birds singing.) - noun after the infinitive, the natural order.
• J'ai vu Marie fermer la porte. (I saw Marie close the door.) - the infinitive has its own object, so the person comes first.
• Je les ai entendus chanter. (I heard them singing.) - they sing, so the participle agrees.
• La chanson que j'ai entendu chanter. (The song I heard sung.) - the song is sung, so no agreement.
• Laissez-moi entrer. (Let me in.) - positive imperative, pronoun after.
• Laisse tomber. (Forget it.)

Common mistakes English speakers make

The commonest error is inserting a linker that the construction refuses: je le vois de venir, laisse-moi à partir. These verbs take a bare infinitive and nothing else. The second is a present participle imported from English: "I hear her singing" is je l'entends chanter, not je l'entends chantant. The third is leaving a pronoun object in front of the infinitive where the English word order suggests it belongs: it is je le vois venir, never je vois le venir, and in a compound tense the pronoun goes in front of the auxiliary, je les ai vus partir. The fourth is agreement by reflex, tacking an s onto every participle with a plural in front of it; the test is whether that plural is the doer of the infinitive, so je les ai vus partir agrees but la chanson que j'ai entendu chanter does not. The fifth is mixing laisser and permettre: le with laisser and a bare infinitive, lui with permettre and de. Finally, do not read laisser tomber literally when somebody says it to you; laisse tomber almost always means "forget it", not that anything has been dropped.

See also

• The faire causatif page covers the causative these verbs share their word order with, and the participle that never agrees.
• The infinitive or subjunctive page covers the three columns of linker, and the à quelqu'un de faire family permettre belongs to.
• The object pronouns page covers the le / lui split and pronoun position in compound tenses.
• The avoir or être page covers the preceding-direct-object agreement rule this page qualifies.
• The present participle and gérondif page covers the -ant form these verbs do not take.
• The French grammar cheatsheet covers the whole A1-B2 grammar map at a glance.