Eu beijo a minha mãe antes de dormir.

Yes — Portuguese often allows subject pronouns to be omitted because the verb ending already shows who the subject is.

So both of these are possible:

• Eu beijo a minha mãe antes de dormir.
• Beijo a minha mãe antes de dormir.

Including eu can add:

• emphasis
• contrast
• clarity

In a neutral sentence, especially in European Portuguese, leaving it out is very common.

Here, beijo is the 1st person singular present tense of the verb beijar.

So:

• beijar = to kiss
• eu beijo = I kiss

A useful thing to notice is that beijo can also be a noun meaning kiss. So the word has two possible roles:

• Eu beijo a minha mãe. → verb
• Um beijo. → noun

In your sentence, it is clearly a verb because it is the action of the sentence.

In European Portuguese, it is very common — and often the normal choice — to use the definite article before a possessive:

• a minha mãe
• o meu pai
• a nossa casa

So a minha mãe is the expected European Portuguese form.

English learners often notice this because English does not use both:

• English: my mother
• Portuguese: a minha mãe

In some contexts, the article can be omitted, but in European Portuguese that often sounds less neutral, more literary, or depends on the expression.

Because they must agree with mãe, which is a feminine singular noun.

So the agreement is:

• a = feminine singular definite article
• minha = feminine singular possessive
• mãe = feminine singular noun

If the noun were masculine, the forms would change:

• o meu pai

This kind of agreement is very important in Portuguese.

No. In this sentence, a is the definite article, meaning the.

That matters because beijar normally takes a direct object:

• beijar alguém = to kiss someone

So in beijo a minha mãe:

• beijo = verb
• a minha mãe = direct object
• a = article, not preposition

This is different from a structure like:

• dou um beijo à minha mãe

There, à does contain a preposition.

Because antes normally appears as antes de before a verb in the infinitive.

So the pattern is:

• antes de + infinitive

Examples:

• antes de sair
• antes de comer
• antes de dormir

So antes de dormir is the correct structure.

Because after antes de, Portuguese uses the infinitive.

So dormir here is not:

• eu durmo
• dorme
• dormi

It stays in the infinitive form:

• dormir

This is very common after prepositions in Portuguese.

Normally, it is understood to be the same person as the subject of the main verb.

So in:

• Eu beijo a minha mãe antes de dormir

the natural reading is:

• I kiss my mother before sleeping / before I go to sleep

If you want to show a different subject, Portuguese can make that explicit, for example:

• antes de ela dormir
• antes de dormirmos

European Portuguese also uses the personal infinitive in some cases, which is one reason this structure is interesting.

Yes. Beijo a minha mãe antes de dormir is perfectly grammatical.

Portuguese often leaves out the subject pronoun when it is clear from the verb ending:

• beijo already tells you the subject is I

So the choice is often about style, emphasis, or context rather than basic grammar.

It can do either, depending on context.

The Portuguese present tense often covers:

• actions happening now
• habits or routines
• general truths

In a sentence like this, many people would naturally understand it as a habit or routine, especially because antes de dormir suggests something regularly done at bedtime.

So it can mean something like a usual action, not only something happening this exact moment.

Yes. A common alternative is:

• Dou um beijo à minha mãe antes de dormir.

This literally uses give a kiss instead of kiss.

Both are natural, but they are built differently:

• beijar alguém → direct object
• dar um beijo a alguém → indirect object with a

In à minha mãe, à is the contraction of:

• a
  • a = à

Your original sentence is completely correct and natural.

Mãe has a nasal sound that English speakers often find tricky.

A few useful points:

• the ã is nasal
• ãe is pronounced as a nasal diphthong
• the accent mark helps show the stressed syllable and the vowel quality

So mãe does not sound like a simple mae with separate vowels. It has a distinctly Portuguese nasal sound.

This is one of the words where listening and repeating is especially helpful.