Minha irmã começou a faculdade este mês e quer escolher uma carreira melhor.

In Portuguese, possessives usually come before the noun:

• minha irmã = my sister
• meu irmão = my brother

The form changes to agree with the noun’s gender and number:

• meu = my (masculine singular)
• minha = my (feminine singular)
• meus = my (masculine plural)
• minhas = my (feminine plural)

Since irmã is feminine singular, you use minha.

These are two different words:

• irmã = sister
• irmão = brother

The ending helps show gender. The ã and ão endings are common in Portuguese and are nasal sounds, so they do not sound like normal English a or o.

Começou is the simple past (also called the preterite) of começar = to begin / to start.

So:

• ela começou = she started / she began

In this sentence, it refers to a completed action in the past: she started college this month.

The accent in começou shows the stressed syllable and helps distinguish pronunciation.

• começou is pronounced roughly co-me-SOU
• The final ou sounds like a single unit

Accent marks in Portuguese are very important because they often show:

• where the stress goes
• sometimes vowel quality
• sometimes the difference between word forms

The a is the feminine singular definite article, meaning the.

• a faculdade = the college / college

Since faculdade is a feminine noun, it takes a.

In Portuguese, articles are used more often than in English. Even where English might just say started college, Portuguese often says started the college / college with an article: começou a faculdade.

Usually, no. This is a very common false friend.

In Brazilian Portuguese:

• faculdade usually means college or university studies
• It can also mean a specific college/school/faculty within a university depending on context

But in everyday speech, começar a faculdade normally means to start college / start university.

So you should not assume it means faculty in the English sense.

Este mês means this month and refers to the current month, the one the speaker is in.

Traditionally, Portuguese distinguishes:

• este = this (near the speaker / the present moment)
• esse = that / this near the listener / something already mentioned
• aquele = that over there / farther away

In real Brazilian Portuguese, people often use esse where grammar books might expect este, so both may be heard. But este mês is perfectly correct and a bit more precise/formal.

Portuguese can express time directly without a preposition in many cases:

• este mês = this month
• hoje = today
• amanhã = tomorrow

So começou a faculdade este mês literally follows the idea started college this month, just like English.

Quer escolher means wants to choose.

• quer = wants (from querer = to want)
• escolher = to choose

This is a very common structure in Portuguese:

• conjugated verb + infinitive

Examples:

• quero estudar = I want to study
• ela quer viajar = she wants to travel
• quer escolher = wants to choose

Because quer is the conjugated form for he/she/it/you.

The verb is querer = to want, but in a sentence you usually conjugate it:

• eu quero = I want
• você quer = you want
• ela quer = she wants

Since the subject is minha irmã, you use the she form: quer.

In Portuguese, adjectives can come after the noun very naturally, and that is often the default position.

• uma carreira melhor = a better career

Putting melhor after the noun sounds neutral and normal here.

You may also see adjective position change for style or emphasis, but carreira melhor is the standard everyday order in this sentence.

These mean different things:

• uma carreira melhor = a better career
  
  • better than her current option, or better than some other option
• a melhor carreira = the best career

So the sentence says she wants to choose a better career, not necessarily the best possible career.

Here, carreira means career / profession path.

It can also mean things like:

• career path
• professional field
• sometimes a course of progression in life or work

In this sentence, because she has started college, escolher uma carreira strongly suggests choosing the professional direction she wants to follow.

Portuguese often leaves out a repeated subject when it is already clear.

So:

• Minha irmã começou a faculdade este mês e quer escolher uma carreira melhor.

naturally means:

• My sister started college this month and wants to choose a better career.

You could say e ela quer, but it is not necessary here because the subject is already obvious.

Yes, depending on context.

In everyday Brazilian Portuguese, começar a faculdade often means:

• to start college/university in general

But it can also imply:

• starting one’s university course or degree program

The exact nuance depends on the situation, but the broad idea is that she has begun higher education.

A rough English-friendly pronunciation is:

MEE-nya eer-MAH co-meh-SOW ah fah-cool-DAH-jee ES-chee mez ee kehr es-coh-LYER OO-mah kah-REY-rah meh-LYOR

A few notes:

• nh in minha sounds like ny in canyon
• irmã has a nasal ending
• d before e in Brazilian Portuguese often sounds like j, so faculdade ends roughly like -DAH-jee
• lh in escolher and melhor is a special sound, somewhat like ly

Yes, it is grammatical and natural.

That said, depending on context, a native speaker might also say something like:

• Minha irmã começou a faculdade este mês e quer escolher uma carreira melhor para o futuro.
• Minha irmã entrou na faculdade este mês e quer escolher uma carreira melhor.

But the original sentence is completely understandable and normal.