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FrenchConjugationSubjonctif

Savoir (to know) · Subjonctif

By TutorLily Editorial Team · Last updated

Savoir in the French subjonctif présent is: je sache, tu saches, il/elle/on sache, nous sachions, vous sachiez, ils/elles sachent. The subjonctif présent of savoir uses the irregular stem 'sach-' across all six persons. 'Il faut que je sache la vérité' = 'I need to know the truth'.

savoir conjugation in the Subjonctif Présent
To KnowSavoir
I know
je sache
you know
tu saches
he/she know
il/elle/on sache
we know
nous sachions
you know
vous sachiez
they know
ils/elles sachent
Examples

Savoir (to know) in context

Sentences that use savoir in the subjonctif. Tap each to hear it.

Il faut que je sache la vérité.

I need to know the truth.

Je veux que tu saches combien je t'aime.

I want you to know how much I love you.

Bien qu'il sache la réponse, il ne dit rien.

Although he knows the answer, he says nothing.

Il faut que nous sachions les détails.

We need to know the details.

J'aimerais que vous sachiez la vérité.

I'd like you to know the truth.

Je doute qu'ils sachent la réponse.

I doubt they know the answer.

Tip

Working with the subjonctif

The subjonctif isn't a tense — it's a mood. It signals doubt, desire, emotion, necessity, or hypothetical possibility. The standard trigger families: "il faut que" (it's necessary), "je veux que" (I want), "je doute que" (I doubt), "avant que" (before), "bien que" (although), "pour que" (so that). The form usually comes from the third-person plural of the present indicative (ils parlent → que je parle). Most -er verbs look identical in subjonctif and indicative for je/tu/il/ils — only the nous/vous forms shift, and only irregular verbs like être (sois), avoir (aie), aller (aille), faire (fasse) need full memorisation.

Questions

Frequently asked questions

How do you conjugate savoir in the subjonctif?
The subjonctif of savoir is: que je sache, que tu saches, qu'il sache, que nous sachions, que vous sachiez, qu'ils sachent. The stem 'sach-' is fully irregular and used across all persons — no stem split.
Why is the subjonctif stem 'sach-' and not 'sav-'?
Savoir's subjonctif preserves an older Latin stem ('sapiam, sapias, sapiat...') that diverged from the regular present stem 'sav-' over centuries. The same kind of preservation explains être (sois), avoir (aie), aller (aille), faire (fasse), pouvoir (puisse). All six are high-frequency verbs whose subjonctif stems were used so often they resisted regularization.
What does '(autant) que je sache' mean?
'Que je sache' or '(autant) que je sache' = 'as far as I know' — a common hedge. 'Pierre est en vacances, que je sache' (Pierre is on vacation, as far as I know). The subjonctif 'sache' here is fossilized into an idiomatic phrase. Equivalent: 'à ma connaissance' (to my knowledge). One of the few subjonctif forms that appears in everyday speech without an explicit trigger.
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More tenses of Savoir (To Know)

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More verbs in subjonctif

All tenses
Savoir (to know)
subjonctif
Être (to be)
subjonctif
Avoir (to have)
subjonctif
Aller (to go)
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