Question formation: intonation / est-ce que / inversion

Summary

Yes/no questions have three forms — rising intonation (casual), est-ce que at the front (neutral) and verb-subject inversion (formal); inversion inserts a euphonic -t- as in a-t-il.

Explanation

French builds yes/no questions in three ways that differ mainly in register. The most casual is to keep statement word order and simply raise the pitch at the end: Tu viens ? (Are you coming?). The neutral, all-purpose way is to put est-ce que at the front of the statement: Est-ce que tu viens ? The most formal way is inversion, swapping the verb and the subject pronoun and joining them with a hyphen: Viens-tu ? All three mean the same thing; you choose by how formal you want to sound.

Information questions add a question word — où (where), quand (when), comment (how), pourquoi (why), combien (how much), que/quoi (what), qui (who). These combine with the same three structures: Où tu vas ? (very casual), Où est-ce que tu vas ? (neutral), Où vas-tu ? (formal). With est-ce que the order is always question word + est-ce que + subject + verb, which makes it the safest pattern for learners because nothing else moves.

Inversion has a pronunciation rule: when a verb ends in a vowel (typically a third-person -e or -a) and is followed by il, elle or on, you insert a euphonic -t- between two hyphens so the words link smoothly. Hence parle-t-il ?, a-t-elle ?, va-t-on ?, mange-t-il ? The -t- is purely phonetic; it is not added when the verb already ends in -t or -d (prend-il ?, dort-elle ?, vend-il ?).

When the subject is a noun rather than a pronoun, full inversion is not used directly; instead French does 'complex inversion', restating the noun and then inverting a matching pronoun: Marie vient-elle ? (Is Marie coming?), Où ton frère travaille-t-il ? In compound tenses, inversion applies to the auxiliary, not the participle: As-tu compris ?, Est-elle partie ? The negative wraps the whole inverted block: N'as-tu pas compris ?

Rule of thumb: in everyday speech, use intonation or est-ce que and you will always be correct and natural; reserve inversion for writing, formal speech and fixed expressions (Comment allez-vous ?, Puis-je vous aider ?). If you do invert and the verb ends in a vowel before il/elle/on, remember the linking -t-. Avoid the common error of mixing patterns, such as « Est-ce que viens-tu ? », which doubles the question marker.

Examples

Tu viens avec nous ? — Are you coming with us? (Intonation question: statement word order, rising pitch (casual).)

Est-ce que tu parles anglais ? — Do you speak English? (Neutral: est-ce que added at the front, no other change.)

Où habite-t-elle ? — Where does she live? (Inversion with euphonic -t- inserted between the vowel-final verb and elle.)

A-t-il fini ses devoirs ? — Has he finished his homework? (In the passé composé, inversion is on the auxiliary a; -t- links a and il.)

Comment allez-vous ? — How are you? (Fixed polite expression using inversion; no -t- because vous starts with a consonant.)

Marie vient-elle ce soir ? — Is Marie coming tonight? (Complex inversion: a noun subject is restated by the pronoun elle.)

Common mistakes

Prerequisites

• Present indicative

Related rules

• Negation: ne … pas
• Subject pronouns
• Liaison