Après le petit-déjeuner, ma sœur lave le bavoir pendant que le bébé joue sur le tapis.

Yes. Après le petit-déjeuner means after breakfast and functions as a time phrase.

A few useful points:

• après = after
• le petit-déjeuner = breakfast
• Together, they set the time for the rest of the sentence.

French often places this kind of time expression at the beginning of the sentence, followed by a comma:

• Après le petit-déjeuner, ma sœur lave le bavoir...

You could also put it later:

• Ma sœur lave le bavoir après le petit-déjeuner...

Both are grammatical, but starting with it gives the time frame first.

French often uses an article where English does not.

So although English usually says after breakfast, French normally says:

• après le petit-déjeuner

That definite article is very natural in French for meals and general routines.

Also, petit-déjeuner here is a noun, meaning breakfast. It is often written with a hyphen.

Compare:

• Je prends le petit-déjeuner. = I eat breakfast / I have breakfast.
• Après le petit-déjeuner... = After breakfast...

Because sœur is a feminine noun, so the possessive adjective must agree with the noun:

• mon = my + masculine singular noun
• ma = my + feminine singular noun
• mes = my + plural noun

So:

• ma sœur = my sister
• mon frère = my brother
• mes parents = my parents

A useful extra point: before a feminine noun beginning with a vowel sound, French often uses mon instead of ma for ease of pronunciation:

• mon amie = my female friend

But sœur begins with a consonant sound, so ma sœur is correct.

Lave comes from laver, which means to wash. It is a very natural choice for washing a bib.

• ma sœur lave le bavoir = my sister washes/is washing the bib

You could sometimes use nettoie from nettoyer (to clean), but it is a little broader and less specific. Laver focuses on washing, usually with water or soap.

So for clothes, hands, a bib, dishes, etc., laver is often the most natural verb.

Le bavoir means the bib.

It is a masculine noun:

• un bavoir = a bib
• le bavoir = the bib

French nouns have grammatical gender, so you need to learn bavoir as masculine. That is why the article is le, not la.

Again, French often uses an article where English may omit one.

Here, le bébé means the baby. It sounds complete and natural in French.

In English, sometimes you might say while baby plays on the rug in a casual context, but French normally wants the article:

• pendant que le bébé joue...

Also, bébé is masculine in grammar when you use le bébé, though in real life it can refer to a baby of any sex.

Pendant que means while.

It introduces a clause describing something happening at the same time as the action in the main clause:

• ma sœur lave le bavoir
• pendant que le bébé joue sur le tapis

So the idea is:

• My sister washes the bib
• while the baby plays on the rug

It is a very common way to express simultaneous actions.

Other ways to say while exist, but pendant que is one of the clearest and most common when both parts have their own subject and verb.

Because pendant que normally takes the indicative, not the subjunctive, when you are talking about a real action happening at the same time.

So:

• pendant que le bébé joue = while the baby plays / is playing

Here, joue is the third-person singular present of jouer.

French uses the present tense in many cases where English may use either:

• plays
• is playing

So le bébé joue can mean either the baby plays or the baby is playing, depending on context.

It can mean either, depending on context.

In this sentence, because it describes a scene, English would often translate it with the progressive:

• My sister is washing the bib while the baby is playing on the rug.

But grammatically, French simply uses the present tense:

• lave
• joue

French does have a structure like être en train de for emphasis:

• Ma sœur est en train de laver le bavoir...
• Le bébé est en train de jouer...

But in ordinary French, the simple present is usually enough.

Yes. Sur usually means on or on top of.

So:

• sur le tapis = on the rug / on the carpet / on the mat

In this sentence, le tapis is the surface where the baby is playing.

A few nearby prepositions to compare:

• sur = on
• sous = under
• dans = in / inside
• à côté de = next to

So joue sur le tapis means the baby is physically on the rug while playing.

Because Après le petit-déjeuner is an introductory phrase placed before the main clause.

In English and French, a comma is often used after this kind of fronted time expression:

• Après le petit-déjeuner, ma sœur lave le bavoir...

It helps mark a pause and makes the sentence easier to read.

It is especially natural in writing when the sentence begins with a longer phrase.

Each verb matches its own subject:

• ma sœur lave
• le bébé joue

Both ma sœur and le bébé are third-person singular, so the verbs are in the il/elle/on form of the present tense.

Conjugations:

• laver → je lave, tu laves, il/elle lave
• jouer → je joue, tu joues, il/elle joue

That is why you see:

• lave
• joue

When it is the noun meaning breakfast, it is commonly written petit-déjeuner.

Examples:

• Le petit-déjeuner est prêt. = Breakfast is ready.
• Après le petit-déjeuner... = After breakfast...

But as a verb phrase, you may also see:

• prendre son petit-déjeuner = to have breakfast
• petit-déjeuner can also exist as a verb in some contexts, though it is much less common in everyday learner material than the noun.

For your sentence, the important thing is that le petit-déjeuner is a noun meaning breakfast.

Not in exactly the same way.

• pendant que = while, emphasizing that two actions happen at the same time
• quand = when, which can simply introduce a time relationship without stressing simultaneity as clearly

So in this sentence:

• pendant que le bébé joue is the best choice for while the baby is playing

If you used quand, it would sound more like when the baby plays/is playing, which is not the same emphasis.

A few useful ones:

• Après → the è gives an open eh sound.
• sœur → the œu sound can be tricky for English speakers.
• bébé → both é sounds are like ay in a clipped way, not like the English word bay.
• bavoir → the end sounds roughly like vwahr.
• pendant que → que is usually a light kuh sound.
• joue → sounds like zhoo.
• tapis → final s is silent.

Also, in natural speech, French rhythm links words smoothly, even when there is no strong English-style stress.

It could be either in pure grammar, because French uses the present tense for both.

But in context, this sentence most naturally describes a scene:

• After breakfast, my sister is washing the bib while the baby is playing on the rug.

If you wanted to make it clearly habitual, context would usually show that:

• Tous les matins, après le petit-déjeuner, ma sœur lave le bavoir pendant que le bébé joue sur le tapis.
• Every morning, after breakfast, my sister washes the bib while the baby plays on the rug.

So the tense alone does not force one interpretation; context does that.