Savoir, Connaître, Ignorer

If there is a single lexical distinction in French that an English speaker must master in the first six months of study, it is the split between savoir and connaître. Both translate to English know, but they are not synonyms — they cover non-overlapping territories. Savoir is for facts, information, and learned skills. Connaître is for being acquainted with people, places, and works of art. A sentence like je sais Pierre is not just slightly off — it is ungrammatical in a way that marks the speaker immediately as a beginner. Add ignorer (the formal "not know") and you have the full system that French uses where English is content with the single verb know.

This page walks through each verb's territory, gives you the conjugations side by side, drills the contrasts that English speakers find most confusing, and warns you about the famous false-friend trap of ignorer (which, in some uses, does mean "ignore" in the English sense — but not the use most learners reach for first). By the end you should be able to pick the right verb without thinking.

Savoir: facts, information, and skills

Savoir is the verb of propositional knowledge — knowing that something is the case, knowing whether, knowing how, knowing where/when/why. The complement of savoir is almost always:

• a clause beginning with que, si, où, quand, pourquoi, comment, qui, ce que — je sais que..., je sais où..., je sais pourquoi...
• an infinitive — je sais nager (I know how to swim)
• the pronoun le standing in for a clause — oui, je le sais (yes, I know)
• a piece of information seen as a discrete fact — je sais son nom, je sais la réponse

What savoir does not take: people, places, books, films, or other objects of acquaintance. For those, use connaître.

Conjugation

Savoir is highly irregular. Memorize the present and the future stem; the rest follows.

The futur/conditionnel stem is saur- (not savoir-) — je saurai, tu sauras, il saura; conditional je saurais, tu saurais. The subjunctive is que je sache, que tu saches, qu'il sache with the unique stem sach-. The everyday formula que je sache ("as far as I know") and its negative tag pas que je sache ("not that I know of") are colloquial fixtures that appear long before learners formally study the subjunctive. The participe présent sachant is also worth memorizing — it appears in the polite formula en sachant que (knowing that...).

Knowing facts and information

The clause structure is the giveaway: anything that can complete I know whether/that/where/why/how/what... is a savoir sentence in French.

Knowing how to do something

Savoir + infinitive = to know how to / to be able to (because you've learned). This is the construction for learned skills — swimming, driving, playing an instrument, speaking a language.

This is one of the cleanest tests for savoir vs pouvoir: if you mean I learned to do X, use savoir; if you mean I am able right now / circumstances permit, use pouvoir. Je sais nager = I have the skill. Je peux nager dans cette piscine = the pool is available, I'm allowed.

Knowing the answer / knowing it

When savoir takes a noun, the noun must be a piece of information seen as a fact — typically la réponse, la vérité, son nom, son adresse, le numéro.

The last example is subtle: je connais la chanson would mean I'm familiar with the song (I've heard it, I recognize it); je sais la chanson means I have memorized it (I can sing it from memory). The same noun, different verb, different meaning.

Le sais-je: the pronominal le of knowledge

When you want to say "I know it" — replacing a whole clause — use the pronoun le:

This le stands in for the whole previous clause. It is invariable (always le, never la or les in this anaphoric use).

Idiom: savoir gré à quelqu'un

The set expression savoir gré à means to be grateful to and is (formal/literary). Je vous saurais gré de bien vouloir... is a fixture in formal letters meaning I would be grateful if you would....

This is (formal) register; in casual speech use merci de or je vous remercie de.

Passé composé peculiarity: j'ai su = "I found out"

In the passé composé, savoir shifts meaning: j'ai su typically means I found out / I learned (the news), not "I knew." For "I knew" in the past, use the imparfait je savais.

This is one of the trickiest aspectual splits in French and trips up advanced learners. See savoir-passe-compose-meaning for the full treatment.

Connaître: acquaintance with people, places, and works

Connaître is the verb of acquaintance. You connaître a person you've met, a city you've been to, a book you've read, a song you've heard. The complement is always a noun (or a noun phrase) — never a clause, never an infinitive.

Conjugation

The headline feature is the circumflex on the î before t — il connaît (NOT connait). The 1990 spelling reform did remove this circumflex officially, so you'll see connait in some texts, but the circumflex form remains overwhelmingly common in print and is what most teachers expect.

Note that the double s in nous connaissons, vous connaissez, ils connaissent is the regular extended stem of -aître verbs (the same pattern in naître, paraître, apparaître). The participe passé is connu, invariable in standard agreement rules except with a preceding direct object pronoun.

Knowing people

You cannot use savoir here. Je sais Pierre is ungrammatical. The verb for being acquainted with a person is always connaître.

Knowing places

Cities, neighborhoods, restaurants, museums, streets — anywhere you can be familiar with by virtue of having been there or knowing about it.

Knowing works of art

Books, songs, films, plays, poems — works you've encountered. Connaître covers them all.

Connaître: meeting / making someone's acquaintance

In the passé composé, j'ai connu can mean I met / I came to know (entered the state of acquaintance). Compare with je connaissais (I was acquainted with — imparfait, ongoing state).

This parallels the savoir shift (j'ai su = found out): both verbs in the passé composé mark the entry into the state of knowing, while the imparfait marks the state of knowing itself.

Connaître par cœur

The expression connaître par cœur means to know by heart. This is one of the few cases where connaître and savoir can both apply — je connais cette chanson par cœur (I know this song by heart, as a familiar work) and je sais cette chanson par cœur (I know it from memory, can recite it). The two are nearly interchangeable here, with savoir slightly emphasizing memorization and connaître slightly emphasizing familiarity.

Ignorer: not knowing (formal) — and the false-friend trap

Ignorer is a regular -er verb that combines two meanings English speakers must keep separate:

1. Not to know / to be unaware of (the primary meaning, formal) — j'ignore son nom (I don't know his name).
2. To ignore (deliberately disregard) — il m'ignore depuis hier (he's been ignoring me since yesterday).

The first meaning is the formal counterpart of je ne sais pas; the second is the meaning that English speakers transfer in. Both exist in modern French, but the first is far more common and is the use that gives ignorer its place in the savoir/connaître/ignorer trio.

Conjugation

Regular -er. No surprises.

Ignorer = ne pas savoir / ne pas connaître (formal)

This is the high-register equivalent of "I don't know." It works with both savoir-style (clauses, infinitives) and connaître-style (nouns) complements.

The set phrase Nul n'est censé ignorer la loi (No one is supposed to be ignorant of the law) is a legal maxim and a useful demonstration of the formal register.

Ignorer = to deliberately ignore

This second meaning — to refuse to acknowledge someone or something — is alive in modern French, especially with persons.

Both senses coexist. Context disambiguates: j'ignore son adresse (I don't know his address) vs je l'ignore (I'm ignoring him / I don't know it — depends on context).

Side-by-side: which verb when?

Common Mistakes

Mistake 1: Using savoir with a person.

This is the cardinal error. Savoir never takes a person as direct object.

Mistake 2: Using connaître with a clause.

Anything starting with que, où, si, pourquoi, comment is savoir, never connaître.

Mistake 3: Connaître + infinitive instead of savoir + infinitive.

Connaître never takes an infinitive complement.

Mistake 4: Translating I knew him as je l'ai su.

The passé composé of connaître means "met"; the passé composé of savoir means "found out." For ongoing past acquaintance, always use the imparfait.

Mistake 5: Forgetting the circumflex on connaît.

The 1990 reform allows connait, but the circumflex connaît is still the dominant written form. Same applies to the futur connaîtra and the infinitive connaître.

Mistake 6: Using ignorer in casual speech for "I don't know."

Ignorer is for written or formal speech. In conversation, je ne sais pas is the default.

Key takeaways

The single biggest lexical distinction in French verbs of mental life is the split between savoir (facts, information, skills, clauses, infinitives) and connaître (persons, places, works of art — anything one is acquainted with). The diagnostic: if you can complete I know that / how / where / why / what / whether..., the verb is savoir. If you can complete I am familiar with / I have met / I have been to, the verb is connaître.

The conjugations differ. Savoir has the irregular futur stem saur-, the unique subjunctive stem sach-, and the participe su. Connaître has the -aît- in the third-person singular (il connaît), the doubled-s in the plural stem (nous connaissons), and the participe connu. Both shift meaning in the passé composé: j'ai su = I found out; j'ai connu = I met. For ongoing past knowledge or acquaintance, always use the imparfait.

Ignorer is the formal "not know" — the higher-register equivalent of ne pas savoir / ne pas connaître. It also has a second meaning, "to deliberately ignore," that overlaps with English. Both senses coexist; context disambiguates. In casual speech, prefer ne pas savoir / ne pas connaître and reserve ignorer for writing and formal contexts.

Drill the trio until savoir Pierre makes you flinch as instinctively as connaître why does. The split will sound automatic within weeks and will permanently elevate the precision of your French.