Savoir in the Passé composé Tense in French

Introduction

Savoir means “to know”, and this page covers exactly one thing: savoir in the passé composé. The passé composé is the tense French speakers reach for when they talk about completed actions in the past — what happened yesterday, last week, or a moment ago. On this page you will find the full passé composé table for savoir, how the tense is formed for this verb, the situations where it is used, how it differs from the imperfect, worked examples, the mistakes learners make most often, an eight-question quiz with explained answers, and answers to the questions students ask about savoir in the passé composé. For example: “J'ai su parler français cette semaine.” — “I have known speak French this week.” Everything on this page uses the forms of savoir exactly as they are conjugated in the passé composé, so you can trust every form you see here.

Savoir in the Passé composé Tense — full table

Person Form
je ai su
tu as su
il/elle a su
nous avons su
vous avez su
ils/elles ont su

Gerund: sachant · Past participle: su

The gerund is sachant, which you use after en for an action happening at the same time as another action. The past participle is su, which you use with avoir in the perfect tenses: the je form of the present perfect is ai su, used for a completed action. Keep both forms in mind as you read the examples below, because the passé composé is only one part of how savoir is used.

How the passé composé of savoir is formed

The passé composé of savoir is formed with the auxiliary avoir in the present plus the past participle su: the auxiliary forms are je ai, tu as, il/elle a, nous avons, vous avez, ils/elles ont. Put the two parts together and you get the table above — for example, the je form is ai su and the ils form is ont su. The participle su never changes its spelling in this table: the verified dump gives the participle in the masculine singular form throughout, and agreement with the subject is a separate step that depends on the sentence.

Because savoir takes avoir as its auxiliary, the passé composé is built the same way as for most French verbs: avoir in the present, then su. That is the first thing to check whenever you build a perfect tense with this verb: reach for avoir, and then add su.

The same participle su appears in the pluperfect, the future perfect and the conditional perfect — only the auxiliary changes tense. Learn the pair “avoir + su” once and you have the key to all four perfect tenses of savoir.

When to use the passé composé of savoir

The passé composé is not a single-purpose tense. Below are the five situations where you will use savoir in the passé composé most often. Each one comes with a real example, so read the rule, then say the example out loud.

1. Knowing speak French — finished

When the action of knowing speak French is finished, the passé composé is the tense to use. It presents the action as complete, with a clear end. Example: “J'ai su parler français cette semaine.” — “I have known speak French this week.”

2. Knowing the answer — finished

The same rule applies to knowing the answer: once the action is done, the passé composé reports it as a completed fact. Example: “Tu as su la réponse cette semaine.” — “You have known the answer this week.”

3. Knowing how to swim for a long time — finished

A third everyday situation is knowing how to swim for a long time, and again the passé composé is right when the action is finished. Example: “Il a su nager depuis longtemps cette semaine.” — “He has known how to swim for a long time this week.”

4. A sequence of completed actions

The passé composé is the tense of the story told step by step: first this happened, then that happened. When you tell someone what you did yesterday, you chain passé composé forms together, one per finished action. Example: “Nous avons su parler français cette semaine.” — “We have known speak French this week.”

5. Recent past and life experience

The passé composé also covers the recent past and things that have happened at some point in your life. With time words such as hier, la semaine dernière or ce matin, the passé composé is the natural choice. Example: “Vous avez su la réponse cette semaine.” — “You have known the answer this week.”

Passé Composé vs Imperfect: how to choose

The closest tense to the passé composé is the imperfect, and learners mix them up constantly. The rule is simple: the imperfect describes an ongoing or habitual past action, while the passé composé describes one finished action. The three pairs below use the same verb, so the only thing that changes is the time frame — and with it, the tense. Notice how the passé composé sentences use words such as tous les jours or hier, while the imperfect sentences use autrefois or quand. Those time words are your best clue when you are choosing a tense.

  • Passé composé: “J'ai su parler français cette semaine.” — “I have known speak French this week.”

  • Imperfect: “Je savais parler français autrefois.” — “I used to know speak French in the past.”

  • The passé composé sentence is about the present moment or one finished action; the imperfect sentence is about the past as it used to be. That difference — now or finished versus ongoing in the past — is the whole decision.

  • Passé composé: “Tu as su la réponse cette semaine.” — “You have known the answer this week.”

  • Imperfect: “Tu savais la réponse autrefois.” — “You used to know the answer in the past.”

  • The passé composé sentence is about the present moment or one finished action; the imperfect sentence is about the past as it used to be. That difference — now or finished versus ongoing in the past — is the whole decision.

  • Passé composé: “Nous avons su nager depuis longtemps cette semaine.” — “We have known how to swim for a long time this week.”

  • Imperfect: “Nous savions nager depuis longtemps autrefois.” — “We used to know how to swim for a long time in the past.”

  • The passé composé sentence is about the present moment or one finished action; the imperfect sentence is about the past as it used to be. That difference — now or finished versus ongoing in the past — is the whole decision.

Example sentences: savoir in the passé composé

Read these eight sentences out loud. They cover all six persons, so by the end you will have seen every form in the table used in a real sentence. Pay attention to the words around the verb — the time expressions, the objects, the other words — because those are what make each sentence sound natural.

  1. “J'ai su la réponse cette semaine.” — “I have known the answer this week.”

  2. “Tu as su nager depuis longtemps cette semaine.” — “You have known how to swim for a long time this week.”

  3. “Il a su parler français cette semaine.” — “He has known speak French this week.”

  4. “Nous avons su la réponse cette semaine.” — “We have known the answer this week.”

  5. “Vous avez su nager depuis longtemps cette semaine.” — “You have known how to swim for a long time this week.”

  6. “Ils ont su parler français cette semaine.” — “They have known speak French this week.”

  7. “J'ai su la réponse cette semaine.” — “I have known the answer this week.”

  8. “Tu as su nager depuis longtemps cette semaine.” — “You have known how to swim for a long time this week.”

Common mistakes with savoir in the passé composé

These are the errors learners actually make with this verb in this tense. Each one shows the wrong version, the right version, and why the correction matters.

  • Wrong: “Je sais parler français hier.” Right: “Je ai su parler français hier.” Why: For one finished action yesterday, use the passé composé ai su, not the present sais. The time word hier points to the past.

  • Wrong: “Je ai su parler français tous les jours.” (said of a daily habit) Right: “Je sais parler français tous les jours.” Why: The passé composé ai su describes one finished action. For something you do every day, use the present sais.

  • Wrong: “Je avoir parler français.” — leaving out the participle Right: “Je ai su parler français.” Why: The passé composé needs both parts: the auxiliary avoir and the participle su. The auxiliary alone is not a complete passé composé.

  • Wrong: “Je savais parler français hier.” (said of one finished action) Right: “Je ai su parler français hier.” Why: The imperfect savais describes an ongoing past situation. For one finished action yesterday, use the passé composé ai su.

Quiz: savoir in the passé composé

Choose the correct answer for each question, then check the answer key. Every answer is explained, so a wrong answer still teaches you something.

1. Complete the sentence: “Je ______ la réponse.”

  • (A) a su
  • (B) avons su
  • (C) ai su
  • (D) as su

2. Complete the sentence: “Tu ______ nager depuis longtemps.”

  • (A) as su
  • (B) ai su
  • (C) a su
  • (D) avons su

3. Complete the sentence: “Il ______ parler français.”

  • (A) ai su
  • (B) as su
  • (C) avons su
  • (D) a su

4. Complete the sentence: “Nous ______ la réponse.”

  • (A) a su
  • (B) avons su
  • (C) ai su
  • (D) as su

5. Complete the sentence: “Vous ______ nager depuis longtemps.”

  • (A) as su
  • (B) a su
  • (C) avez su
  • (D) ai su

6. Complete the sentence: “Ils ______ parler français.”

  • (A) ai su
  • (B) as su
  • (C) a su
  • (D) ont su

7. What does savoir mean in English?

  • (A) to see
  • (B) to take
  • (C) to know
  • (D) to come

8. What is the past participle of savoir?

  • (A) su
  • (B) venu
  • (C) vu
  • (D) pris

Answer key

  1. C) ai su — The je form is ai su.
  2. A) as su — The tu form is as su.
  3. D) a su — The il/elle form is a su.
  4. B) avons su — The nous form is avons su.
  5. C) avez su — The vous form is avez su.
  6. D) ont su — The ils/elles form is ont su.
  7. C) to know — savoir means “to know”. The other options are the meanings of different verbs.
  8. A) su — The past participle of savoir is su; the passé composé is formed with avoir + su.

Frequently asked questions

How is the passé composé of savoir formed?

With the auxiliary avoir in the present plus the past participle su: je ai su, tu as su, il a su, nous avons su, vous avez su, ils ont su.

When do I use the passé composé of savoir?

Use the passé composé for completed actions in the past, especially in spoken French — for example, “J'ai su parler français cette semaine.” — “I have known speak French this week.” For an ongoing or habitual past action, use the imperfect instead.

What is the difference between the passé composé and the imperfect of savoir?

The passé composé reports one finished action; the imperfect describes background, habit or an action in progress in the past. Compare “J'ai su parler français cette semaine.” with “Je savais parler français autrefois.” — the first is finished, the second is ongoing in the past.

Pronunciation

Pronunciation is not listed on this page: the verified tables do not include IPA for savoir, so no pronunciation is given rather than an invented one.

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