Por la noche, me quito el rímel antes de dormir.

In Spanish, por la noche is the normal way to mean at night / in the evening / at nighttime in a general sense.

So:

• Por la noche, me quito el rímel... = At night, I take off my mascara...

A native English speaker may expect en la noche, but that is much less common in standard Spanish from Spain for this kind of routine statement.

Useful comparisons:

• por la mañana = in the morning
• por la tarde = in the afternoon / evening
• por la noche = at night

Because the verb here is being used as quitarse, which often means to remove something from oneself.

• quitar = to remove, to take away
• quitarse = to take off, to remove from yourself

So:

• Me quito el rímel = I take off my mascara
• literally: I remove the mascara from myself

The me shows that the action affects the speaker's own body or appearance.

Compare:

• Quito la taza de la mesa = I remove the cup from the table
• Me quito el abrigo = I take off my coat
• Me quito el rímel = I remove my mascara

Spanish often uses the definite article (el, la, los, las) with body parts, clothing, and personal items when it is already obvious who they belong to.

So instead of saying my mascara, Spanish naturally says the mascara:

• Me quito el rímel = literally I remove the mascara
• but in natural English: I take off my mascara

This pattern is very common:

• Me lavo las manos = I wash my hands
• Me cepillo los dientes = I brush my teeth
• Me pongo el abrigo = I put on my coat

Spanish prefers the article because the me already tells us whose mascara it is.

Yes, rímel is common and easily understood in Spain. It refers to mascara.

Another very common term is:

• máscara de pestañas = mascara

Both are correct. In everyday speech, many people say rímel, while máscara de pestañas can sound a bit more explicit or formal.

So these are both natural:

• Me quito el rímel
• Me quito la máscara de pestañas

Yes, rímel is usually treated as masculine in standard Spanish:

• el rímel

That is why the sentence says:

• me quito el rímel

With máscara de pestañas, the main noun is máscara, which is feminine:

• la máscara de pestañas

So the gender depends on the noun you choose.

The written accent shows where the stress falls:

• rí-mel

Without the accent, Spanish spelling rules would suggest a different stress pattern. The accent makes the pronunciation clear.

For a learner, the important point is:

• pronounce the first syllable more strongly: RÍ-mel

The present tense in Spanish is often used for habits or routines, just like in English.

So:

• Por la noche, me quito el rímel antes de dormir. means something like
• At night, I take off my mascara before going to sleep.

It describes what the speaker normally does, not necessarily what they are doing right this second.

After antes de, Spanish uses an infinitive when the subject stays the same.

So:

• antes de dormir = before sleeping / before going to sleep

You cannot use a conjugated verb directly after antes de in this structure.

Correct:

• antes de dormir
• antes de comer
• antes de salir

Not correct here:

• antes de duermo
• antes de dormí

Yes, you can. Both are possible, but they feel slightly different.

• antes de dormir = before sleeping / before going to sleep
• antes de dormirme = before falling asleep / before I go to sleep myself

Adding the reflexive pronoun can make it feel a bit more personal or can emphasize the act of going to sleep.

In many everyday situations, antes de dormir is the simpler and more neutral choice.

In this sentence, antes de dormir is best understood as before going to sleep / before sleeping.

In real usage, Spanish often allows dormir to cover both ideas depending on context.

If you want to be more explicit, you could say:

• antes de irme a dormir = before going to bed / before going to sleep
• antes de acostarme = before going to bed

But the original sentence is completely natural.

The comma is used because Por la noche is an introductory time phrase placed at the beginning of the sentence.

• Por la noche, me quito el rímel antes de dormir.

This comma helps separate the time expression from the main clause. In informal writing, some people may leave it out, but using it is perfectly good punctuation.

You could also put the time phrase later:

• Me quito el rímel por la noche antes de dormir.

That is grammatical too, though the original version sounds very natural and nicely organized.

Sometimes, but not always with exactly the same feel.

• por la noche usually refers to at night / in the evenings as part of a routine
• de noche often means at night in a more general or descriptive sense

For this sentence about a personal habit, por la noche is the more natural choice.

Examples:

• Por la noche estudio. = I study at night / in the evenings.
• Los gatos ven bien de noche. = Cats see well at night.

They are related, but not exactly identical.

• quitarse el rímel = to remove your mascara
• desmaquillarse = to remove your makeup

So desmaquillarse is broader. It could include foundation, eyeliner, lipstick, mascara, and so on.

Compare:

• Por la noche, me quito el rímel. = At night, I take off my mascara.
• Por la noche, me desmaquillo. = At night, I remove my makeup.

If the speaker specifically means mascara, me quito el rímel is more precise.

No. With a conjugated reflexive verb, the reflexive pronoun goes before the verb:

• me quito

Not:

• quito me

But with an infinitive, the pronoun can attach to the end:

• quitarme
• dormirme

That is why you can say:

• antes de dormirme

So the rule here is:

• conjugated verb: me quito
• infinitive: quitarme, dormirme

The sentence is:

• Por la noche, me quito el rímel antes de dormir.

Its structure is:

• Por la noche = time expression
• me quito = verb phrase
• el rímel = object
• antes de dormir = another time expression

So, very roughly:

At night, I remove the mascara before sleeping.

This is a very normal Spanish word order. Spanish is somewhat flexible, but this version sounds natural and clear.