In short

At C1 you shift between registers (formal soutenu, neutral courant, casual familier), you highlight information with mise en relief (c’est…qui/que), you compress verbs into nouns (nominalisation), and you recognise the literary tenses (passé simple, passé antérieur, imparfait du subjonctif). The key rule: match your grammar and vocabulary to the situation, and know the written-literary forms even if you rarely produce them.

The rule

Registers: soutenu / courant / familier

French makes constant choices between three levels. The same idea changes word, syntax, and even tense depending on who you speak to.

• Soutenu (formal, literary, official): full negation, nous, inversion questions, elevated vocabulary. Nous n’avons rien constaté.
• Courant (everyday neutral, safe default): on or nous, est-ce que, standard words. On n’a rien vu.
• Familier (casual, spoken, friends): dropped ne, on for nous, intonation questions, slang. On a rien vu.

Signals that move you up or down the scale:

Practical rule: in writing and with strangers, keep the ne, avoid slang, and prefer nous or a neutral on. Never mix a slang word into an otherwise formal sentence.

Mise en relief: c’est…qui/que, ce qui…c’est

French has fixed word order, so to emphasise one element you frame it in a cleft construction instead of stressing it with your voice.

• c’est + [subject] + qui highlights the subject: C’est Marie qui a tout organisé. (It’s Marie who organised everything.)
• c’est + [object/complement] + que highlights anything else: C’est à Paris que je l’ai rencontré. (It’s in Paris that I met him.)
• ce qui / ce que … c’est fronts a whole idea: Ce qui m’agace, c’est son retard. / Ce que je veux, c’est la paix.
• With a plural highlighted subject, the verb still agrees: Ce sont mes parents qui décident.

The verb inside qui agrees with the highlighted noun (including its person): C’est moi qui suis responsable (not qui est).

Nominalization

Nominalisation turns a verb or adjective into a noun. It makes a sentence denser and more formal, and is the backbone of headlines, reports, and administrative French.

• From a verb (often with a suffix): arriver -> l’arrivée, construire -> la construction, développer -> le développement, fermer -> la fermeture.
• From an adjective: lent -> la lenteur, libre -> la liberté, pauvre -> la pauvreté.
• Headline style drops the verb entirely: Le président est arrivé -> Arrivée du président. / Les prix ont augmenté -> Hausse des prix.

The noun’s gender depends on the suffix: -tion, -sion, -ure, -eur (abstract), -té, -ée are feminine; -ment, -age, -isme are masculine.

Literary tenses (recognition, with passé simple production)

These tenses live in written narrative and formal prose; you should read them fluently and produce the passé simple in a story.

• Passé simple (production): the narrative past of literature and history, replacing passé composé for completed foreground actions. Il entra, regarda autour de lui et sortit.
• Passé antérieur (recognition): avoir/être in the passé simple + past participle; marks an action just before another in a literary text, after quand, dès que, lorsque. Quand il eut fini, il partit.
• Imparfait du subjonctif (recognition): the subjunctive used after a past main verb in very formal prose; today replaced by the present subjunctive. Il fallait qu’il partît. (modern: qu’il parte).

Forms & patterns

Cleft agreement of the verb after c’est…qui:

Passé simple endings (production):

Passé antérieur and imparfait du subjonctif (recognition):

Common nominalisation suffixes:

Examples

Common mistakes

• C’est moi qui a raison -> C’est moi qui ai raison - the verb after qui agrees with moi (1st person).
• C’est les voisins qui… -> Ce sont les voisins qui… - use ce sont before a plural noun in careful register.
• Je sais pas, monsieur le directeur -> Je ne sais pas - keep the ne in formal or written register.
• l’augmentation de les prix -> l’augmentation des prix - nominalised phrases still contract de + les -> des.
• Il entrait, regardait et sortait (as foreground narration) -> Il entra, regarda et sortit - completed narrative actions take the passé simple, not the imparfait.
• Quand il a eu fini, il partit (mixing registers) -> Quand il eut fini, il partit - stay in the literary system: passé antérieur with passé simple.

Tips

• Pick one register and stay in it; the fastest tell of a learner is a slang word inside a formal sentence.
• To choose qui vs que in a cleft: qui if the highlighted word is the subject, que for everything else.
• Nominalise to sound formal and to write headlines; un-nominalise (back to a verb) to sound natural in speech.
• Learn the passé simple mainly in the third person - that is where literature uses it most.
• You only need to recognise the passé antérieur and imparfait du subjonctif; in your own writing use plus-que-parfait and present subjunctive instead.
• Spot the imparfait du subjonctif by its circumflex and -ât/-ît/-ût or -ssent endings - then read it as an ordinary subjunctive.