Min mor synger en vuggevise, før hun putter babyen om aftenen.

Because mor is a common gender singular noun in Danish.

The possessive forms are:

• min for common gender singular
• mit for neuter singular
• mine for plural

So:

• min mor = my mother
• mit barn = my child
• mine forældre = my parents

After a possessive word like min, din, hans, hendes, Danish normally uses the noun in its basic indefinite form, not the definite form.

So you say:

• min mor = my mother
• hendes baby = her baby
• vores hus = our house

Not:

• min moren
• hendes babyen
• vores huset

This is a very common difference from how English learners sometimes expect Danish to work.

Synger is the present tense of at synge = to sing.

In Danish, verbs do not change depending on the person:

• jeg synger = I sing / I am singing
• du synger = you sing
• hun synger = she sings

So min mor synger simply means my mother sings.

Because vuggevise is a common gender noun, so its indefinite singular article is en.

• en vuggevise = a lullaby
• vuggevisen = the lullaby

This noun is made up of:

• vugge = cradle
• vise = song/ballad

So the word literally has the idea of a cradle song.

Because they are being used differently.

• en vuggevise means a lullaby — any lullaby, not a specific one already identified.
• babyen means the baby — a specific baby known from the context.

In Danish, the definite form is often made by adding an ending to the noun:

• en baby = a baby
• babyen = the baby

So the sentence is talking about a lullaby in general, but the baby as a specific child.

Here putter means something like puts to bed, tucks in, or settles for sleep.

The verb at putte can mean to put/place something somewhere, but with children it often has the special meaning of putting a child to bed.

So:

• hun putter babyen = she puts the baby to bed / tucks the baby in

A more explicit alternative would be:

• hun lægger babyen i seng = she puts the baby to bed

But putter babyen sounds very natural in everyday Danish.

Because før introduces a subordinate clause.

In Danish subordinate clauses, the normal order is:

• subject + verb

So:

• før hun putter babyen = before she puts the baby to bed

That is different from the main clause word order rules in Danish, where the verb often comes early because of V2 word order.

Compare:

• Min mor synger... = main clause
• før hun putter babyen... = subordinate clause

If you started the whole sentence with the før-clause, you would get:

• Før hun putter babyen om aftenen, synger min mor en vuggevise.

Now the main clause shows inversion: synger min mor.

Hun refers to min mor.

So the meaning is:

• My mother sings a lullaby before she puts the baby to bed in the evening.

Even though babyen appears later in the sentence, hun naturally points back to mor.

Om aftenen means in the evening or in the evenings, depending on context.

Here it gives a habitual time setting: this is something that happens as part of the evening routine.

A useful contrast is:

• om aftenen = in the evening / in the evenings, generally
• i aften = tonight, this specific evening

So in this sentence, om aftenen suggests a regular bedtime routine, not just one particular night.

Because før hun putter babyen om aftenen is a subordinate clause, and Danish often places a comma before such clauses.

So the comma helps mark the structure:

• Min mor synger en vuggevise, før hun putter babyen om aftenen.

You may also see Danish without this comma in some modern writing styles, but many learners will encounter sentences written this way.

Yes.

The Danish present tense synger can cover both:

• My mother sings a lullaby
• My mother is singing a lullaby

The exact meaning depends on context.

If you want to make the ongoing action especially clear in Danish, you would usually add context rather than change the verb form. Danish does not have a separate tense that works exactly like the English is singing form.