Amanhã o namorado dela quer apresentar a Ana à mãe dele.

Amanhã means tomorrow, and Portuguese often puts time expressions at the beginning of the sentence to set the context right away.

So:

Amanhã o namorado dela quer apresentar a Ana à mãe dele.
= Tomorrow, her boyfriend wants to introduce Ana to his mother.

You could also say:

O namorado dela quer apresentar a Ana à mãe dele amanhã.

That is also correct. Starting with amanhã just gives extra emphasis to when this will happen.

In Portuguese, it is very common to use the definite article with nouns in places where English would not.

So:

• o namorado dela = her boyfriend
• literally: the boyfriend of hers

This sounds completely normal in Portuguese. In English, we usually do not say the her boyfriend, but Portuguese structure works differently.

Dela means of her / hers, and dele means of him / his.

Portuguese often prefers dela/dele instead of seu/sua when there could be confusion.

For example:

• o namorado dela = her boyfriend
• a mãe dele = his mother

If the sentence used sua mãe, that could be ambiguous, because sua might refer to different people depending on context. Using dele/dela makes it much clearer.

In Portuguese, just like in English, the present tense can be used to talk about a near or planned future, especially when there is a time word like amanhã.

So:

• quer apresentar = wants to introduce
• with amanhã, the whole sentence clearly refers to the future

This is very natural. Portuguese could also use other future forms in different contexts, but here the present works perfectly well.

In this sentence, apresentar means to introduce.

The pattern is:

apresentar alguém a alguém
= to introduce someone to someone

So here:

• apresentar a Ana = introduce Ana
• à mãe dele = to his mother

So the structure is:

[someone] quer apresentar [person introduced] a [person receiving the introduction]

In this sentence:

• the boyfriend = the one doing the introducing
• Ana = the person being introduced
• his mother = the person she will be introduced to

That a is not the feminine article here. It is the personal marker used with a direct object that is a person in this construction.

With apresentar, the person being introduced often appears after apresentar with a:

• apresentar a Ana
• apresentar o João
• apresentar a minha amiga

Also, in many varieties of Portuguese, especially in Brazil, people often use the definite article before first names:

• a Ana
• o João

So learners may see this as a combination of:

• the verb pattern
• and the common article before personal names

In practice, a Ana here is completely natural.

À is a contraction of:

• a = to
• a = the (feminine singular article)

So:

• a mãe = the mother
• a + a mãe = à mãe = to the mother

This accent is called crase.

So:

• apresentar a Ana à mãe dele = to introduce Ana to his mother

A very useful way to think about it is:

• apresentar alguém a alguém
• if that second alguém is feminine and has a as its article, then a + a = à

Yes, in some contexts you can say just Ana, but in Brazilian Portuguese it is very common to use definite articles before people’s names:

• a Ana
• o Pedro
• a Carla

This varies by region and by style. In Brazil, using the article is often the most natural choice in everyday speech.

So:

• apresentar Ana à mãe dele
• apresentar a Ana à mãe dele

Both may be understood, but a Ana sounds very natural in many Brazilian contexts.

Here, dele refers to o namorado.

So the sentence means that her boyfriend wants to introduce Ana to his own mother.

That is:

• dela → refers to some woman, the one who has the boyfriend
• dele → refers to the boyfriend

Portuguese uses dela/dele to keep these relationships clear.

A little, yes—but much less than it would be with sua.

The sentence has three important people in it:

• ela = the woman whose boyfriend it is
• o namorado dela = her boyfriend
• a Ana = Ana

Then dele most naturally refers to the boyfriend, so:

Tomorrow her boyfriend wants to introduce Ana to his mother.

Without context, a learner might wonder whether dela and Ana are the same person, but normally they are understood as different people unless the context says otherwise.

Because Portuguese usually follows the same logical pattern as English here:

introduce [person] to [someone]

So:

• apresentar a Ana à mãe dele = introduce Ana to his mother

If you reversed them, the meaning would change:

• apresentar a mãe dele à Ana = introduce his mother to Ana

Both are grammatical, but they do not mean the same thing.

No. They are related, but not the same.

• apresentar alguém a alguém = to introduce someone to someone
• apresentar-se = to introduce oneself / to present oneself

Examples:

• Ele quer apresentar a Ana à mãe dele.
  = He wants to introduce Ana to his mother.

• Ana quer se apresentar à mãe dele.
  = Ana wants to introduce herself to his mother.

That little se makes an important difference.