What this is
You already know how to ask a yes/no question — est-ce que has been in your sentences since M3. What’s new here is naming all three ways French does it, and adding the one you haven’t touched yet: inversion, where the subject and verb swap places. All three ask exactly the same question; they differ only in register.
The rule
| Register | Pattern | Example |
|---|---|---|
| Spoken, casual | Statement + rising intonation | Tu travailles aujourd’hui ? |
| Neutral, any context | est-ce que + statement | Est-ce que tu travailles aujourd’hui ? |
| Formal, written | Verb-hyphen-subject | Travailles-tu aujourd’hui ? |
Inversion is mechanical: take the statement, move the subject pronoun after the verb, and join them with a hyphen.
Tu travailles. → Travailles-tu ?
Vous avez faim. → Avez-vous faim ?One wrinkle. When the subject is il, elle, or on and the verb ends in a vowel sound, French inserts -t- between them so the two vowels don’t run together:
Il travaille. → Travaille-t-il ? (not Travaille-il, two vowels colliding)
Elle a faim. → A-t-elle faim ?
On mange bien. → Mange-t-on bien ?nous and vous never need it — avons, avez, sommes, êtes all already end in a consonant sound, so there’s nothing to separate.
A noun can’t invert directly. French doesn’t produce Travaille Marie ? — the noun stays in front, and a pronoun matching its gender and number goes after the verb instead:
Marie travaille. → Marie travaille-t-elle ?
Le professeur a raison. → Le professeur a-t-il raison ?Negation wraps the whole thing. ne goes at the very front, pas at the very end — everything in between, including the hyphenated verb-subject block, stays untouched:
Ne travaille-t-il pas aujourd'hui ?n’est-ce pas, tacked onto the end of literally any statement, works as a universal tag question — “isn’t that so?” It doesn’t agree with anything or change form, which makes it the easiest question tool in this whole concept.
Why it works this way
Historically, French questions were always formed by inversion — est-ce que is a comparatively recent workaround, literally “is it that,” which lets you ask a question by adding a fixed phrase to the front instead of rearranging anything. Spoken French has drifted even further from inversion, defaulting to plain rising intonation because it requires no rearrangement at all. The three registers you’re learning here aren’t three unrelated rules; they’re three points along one historical drift, still all in active use depending on formality.
Edge cases
The -t- has no meaning
It’s pure sound, inserted only to keep two vowels from colliding. It never appears with tu, nous, or vous inversion, and it never appears when the verb itself already ends in a consonant sound (Part-il ? needs nothing extra, though this course hasn’t taught partir).
A noun subject always gets echoed by a pronoun
This is the single most common error for a learner extending the tu/il pattern too literally. The noun never moves; only its pronoun echo inverts with the verb.
n’est-ce pas doesn’t inflect
It’s invariant regardless of the person, number, or tense of the sentence it’s tagging — the “universal” part of universal tag question is not an exaggeration.
What English speakers get wrong here
English inversion (“Are you…”, “Is he…”) only works with a small set of auxiliary-like verbs and never needs an inserted sound, so the -t- insertion feels arbitrary at first — it helps to remember it is arbitrary, purely phonetic, and never has to be reasoned about semantically. The other common slip is inverting a noun subject directly, because English does exactly that (“Works Marie today?” would be the literal parallel, and it’s exactly as wrong in French as it sounds in English).