In French, the relative pronouns ‘qui’ and ‘que’ fulfil distinct and fundamental grammatical functions in linking clauses, depending primarily on the role of the antecedent in the subordinate clause.
The main functions are as follows:
1. The relative pronoun “Qui” (subject function)
The primary grammatical function of ‘qui’ is to act as the subject performing the action in the subordinate clause.
Versatile reference: Contrary to popular belief, it is not limited to people; it can refer to things, animals, people or concepts, provided they fulfil the role of subject.
Grammatical structure: A handy rule for identifying it is that ‘qui’ is almost always followed by a conjugated verb. In the following sentence, the pronoun ‘qui’ is the subject of the verb ‘to help’:
L’homme qui m’a aidé
The man who helped me
2. The relative pronoun ‘Que’ (used as a direct object)
The pronoun Que functions as the direct object (direct complement) of the sentence.
Reference: Like ‘qui’, it can refer to both living beings and inanimate objects.
Phonetic modification: It is important to note that, due to rules of elision, it becomes qu’ when the subject following it begins with a vowel. It is essential not to confuse this rule with the behaviour of the relative pronoun qui. Unlike que, the pronoun qui is strictly invariable.
This distinction acts as a ‘syntactic safety mechanism’: in spoken language, hearing an elision (qu’il) immediately indicates that the pronoun is a direct object, whilst retaining the vowel ‘i’ (qui il — although grammatically it is usually qui + verb —) confirms that it is the subject
Grammatical structure: To distinguish it, note that ‘que’ must be followed by a subject (often a personal pronoun such as ‘je’, ‘tu’, ‘il’, etc.) which is the one performing the action. In the following sentence, ‘el libro’ is the direct object of the action performed by the subject ‘I’ (‘je’).
Le livre que j’ai lu
El libro que leí
Summary of key differences
To make it easier to use, look at the word that follows the pronoun:
Qui + Verb: Used when the pronoun is the subject.
Que + Subject: Used when the pronoun functions as the direct object.
Although in English both are usually translated as “that,” in French the distinction is strictly functional: “qui” replaces the subject and “que” replaces the direct object.