Le soir, sa mère pose la couverture près du berceau avant de chanter une berceuse.

Here Le soir is a time expression meaning in the evening or at night.

French often uses le + time word to express a habitual time:

• Le matin = in the morning
• L’après-midi = in the afternoon
• Le soir = in the evening

So this sounds like something that happens regularly, not just once.

The comma separates the opening time phrase from the rest of the sentence.

French often puts a time expression at the beginning for emphasis or context:

• Le soir, sa mère...

This is similar to English:

• In the evening, her mother...

The comma is natural and helps readability, though in some short French sentences punctuation can be flexible.

Because the possessed noun is mère, which is feminine.

In French, possessive adjectives agree with the thing possessed, not with the owner:

• sa mère = his mother / her mother
• son père = his father / her father

So sa is used because mère is feminine singular.

It can mean either his mother or her mother.

French sa does not tell you whether the owner is male or female. It only matches the gender of the noun being possessed:

• sa mère = his mother / her mother
• sa couverture = his blanket / her blanket

You need context to know whose mother it is.

Pose is in the present tense: third person singular of poser.

• je pose
• tu poses
• il/elle pose

In this sentence, sa mère pose means her/his mother places/puts.

The French present tense can often translate to:

• puts
• is putting
• sometimes a habitual puts

Depending on context, it may describe a routine action.

Poser means to place, to set down, or to lay something somewhere.

So pose la couverture suggests placing the blanket carefully in a particular spot.

Met from mettre is also possible in many contexts and often means puts in a more general way.
The difference is roughly:

• poser = place/set down
• mettre = put

Here poser feels a bit more deliberate.

French uses articles more often than English.

Here la couverture means the blanket. It suggests a specific blanket already known from the situation.

French usually requires an article before a noun:

• la couverture
• le berceau
• une berceuse

English sometimes drops articles where French does not, but French generally keeps them.

Because de + le contracts to du.

So:

• près de le berceau → près du berceau

This is a standard contraction in French:

• de + le = du
• de + les = des

But:

• de + la stays de la
• de + l’ stays de l’

So:

• près du berceau = near the cradle
• près de la fenêtre = near the window

Berceau usually means cradle.

It refers to a baby’s small bed, often one that can rock. Depending on context, an English translation might sometimes say crib, but cradle is the more direct match.

After avant, when the same subject continues with an infinitive verb, French uses avant de + infinitive.

So:

• avant de chanter = before singing / before she sings

This works because the subject is still sa mère:

• sa mère pose... avant de chanter...

If the subject changed, French would usually use avant que + a conjugated verb:

• avant qu’il parte = before he leaves

Grammatically, yes, but it changes the structure.

• avant de chanter is preferred when the subject is the same.
• avant qu’elle chante would sound more explicit and usually less natural here.

So in this sentence, avant de chanter is the normal choice because the mother is doing both actions.

Une berceuse means a lullaby.

It comes from the verb bercer, which means to rock or to soothe, especially a baby.

So chanter une berceuse means to sing a lullaby.

Une is the indefinite article, meaning a.

So chanter une berceuse means she sings a lullaby, not a specific previously identified lullaby.

Compare:

• une berceuse = a lullaby
• la berceuse = the lullaby

Yes, it is very natural.

The structure is:

• Le soir = time expression
• sa mère = subject
• pose = verb
• la couverture = direct object
• près du berceau = place
• avant de chanter une berceuse = action that happens afterward

A rough grammar map:

• Time + subject + verb + object + place + before + infinitive

French often places time expressions at the beginning like this.

It most naturally suggests a habit or routine.

That comes especially from Le soir, which often means in the evening in a general, repeated sense.

So the sentence sounds like part of a bedtime routine:

• In the evening, her mother places the blanket near the cradle before singing a lullaby.

If French wanted to make it clearly about one single event, it would often use a more specific time marker or a past tense, depending on context.