Verbes de sensation : Accord
French verbs of perception are subject to grammatical agreement in the compound tenses, but the rules are somewhat tricky. Unlike other avoir verbs, which agree with their direct objects when they precede the verb, verbs of perception agree with their subjects when they precede the verb.
So there are two questions to ask in order to figure out whether you need agreement.
1) Does the noun / pronoun precede the verb?
Il a vu peindre la maison. | He saw the house being painted. | |
J’ai entendu aboyer les chiens. | I heard the dogs barking. |
This part is easy: If it follows the verb, as in the above examples, there is no agreement – you’re done. If it precedes the verb, go on to the second question.
2) Is the noun / pronoun the subject or the object of the infinitive?
This is more complicated – how do you know whether it’s the subject or object? You have to carefully consider the noun / pronoun: is it performing the action of the infinitive or being performed on? If it’s the latter, it’s the object and there is no agreement – you’re done.
La maison qu’il a vu peindre. | The house he saw being painted. | |
Il l’a vu peindre. | He saw it being painted. |
Otherwise, if the noun or pronoun is doing the action, it’s the subject and requires agreement.
Les chiens que j’ai entendus aboyer. | The dogs I heard barking. | |
Je les ai entendus aboyer. | I heard them barking. |
Par exemple…
J’ai entendu les étudiants mener la discussion. | I heard the students leading the discussion. | |
La discussion que j’ai entendu mener les étudiants. | The discussion I heard the students leading. | |
La discussion que je les ai entendus mener. | The discussion I heard them leading. | |
Je les ai entendus mener la discussion. | I heard them leading the discussion. | |
Je les ai entendus la mener. | I heard them leading it. |
Further reading
Page 1: Introduction to verbs of perception
Page 2: Word order with verbs of perception
Page 3: Agreement with verbs of perception

I was making some sentences of my own and I was wondering whether the first, original sentence of this example would be reconstructed in these ways below, and whether these ways were correct or not.
Il a vu les pâtissiers cuire les gâteaux. Les gâteaux qu’il a vu cuire les pâtissiers. Les gâteaux qu’il les a vus cuire. Il les a vus cuire les gâteaux. Il les a vus les cuire.
Thank you, Joseph
Bonjour Joseph,
You’ve chosen a tricky verb, cuire, which is more for cooking on the stove as opposed to in the oven, plus it’s usually causative (faire cuire). So I’m going to change the verb to préparer to avoid those issues.
That said,
Il a vu les pâtissiers préparer les gâteaux. Les gâteaux qu’il a vu préparer les pâtissiers. Les gâteaux qu’il les a vus préparer. Il les a vus préparer les gâteaux. Il les a vus les préparer.
are all correct. Chapeau!