Learn Hardcore Portuguese (Portugal): Eu fico orgulhoso quando a minha irmã cumpre o seu objetivo. - I feel proud when my sister achieves her goal.

ser orgulhoso – means “to be a proud person” as a more permanent characteristic (often with a negative nuance: arrogant, full of pride).
estar orgulhoso – means “to be proud (right now)”, focusing on a temporary state at a given moment.
ficar orgulhoso – literally “to become / get proud”, often used when something makes you feel proud or you end up feeling proud as a reaction.

In this sentence, “Eu fico orgulhoso quando…” expresses a repeated reaction: every time she achieves her goal, I (then) feel proud. So “fico” (from ficar) fits better than sou (permanent trait) or estou (state right now but without the idea of “as a result of something”).

You could say “Eu estou orgulhoso” in a specific situation:

“Hoje estou muito orgulhoso da minha irmã.” – Today I’m very proud of my sister.

But to express the usual reaction whenever she meets her goal, “fico orgulhoso” is the most natural.

If I’m a woman speaking, do I say “orgulhoso” or “orgulhosa”?

The adjective must agree in gender with the speaker (the subject eu), not with irmã.

A man would say: “Eu fico orgulhoso…”
A woman would say: “Eu fico orgulhosa…”

So you change the ending -o → -a for a female speaker:

orgulhoso (masculine)
orgulhosa (feminine)

Everything else in the sentence can stay the same.

Why is it “a minha irmã” and not just “minha irmã”?

In European Portuguese, it is very common and natural to use the definite article before possessives:

a minha irmã – my sister
o meu irmão – my brother
a minha casa – my house

Saying just “minha irmã” is not grammatically wrong, but in Portugal it often sounds:

more formal,
poetic/literary, or
a bit “foreign”/influenced by Brazilian Portuguese.

In Brazilian Portuguese, dropping the article (“minha irmã”) is more usual in everyday speech. In Portugal, the default is with the article: “a minha irmã”.

Why is it “a minha irmã” (feminine) but “meu” is masculine in other phrases like “o meu irmão”?

The possessive agrees in gender and number with the noun it modifies, not with the possessor:

a minha irmã – my sister (irmã is feminine singular → minha)
o meu irmão – my brother (irmão is masculine singular → meu)
as minhas irmãs – my sisters
os meus irmãos – my brothers

So:

meu / meus → for masculine nouns
minha / minhas → for feminine nouns

It has nothing to do with whether I (the possessor) am male or female; it’s about irmã / irmão / casa / carro, etc.

Could I drop the “Eu” and just say “Fico orgulhoso quando a minha irmã cumpre o seu objetivo”?

Yes. Subject pronouns are often omitted in Portuguese because the verb ending already shows who the subject is:

(Eu) fico – I become/get
(Tu) ficas – you (singular, informal) become/get
(Ele / Ela) fica – he/she becomes/gets

So “Fico orgulhoso quando a minha irmã cumpre o seu objetivo.” is grammatically correct and very natural.

Including “Eu” adds a bit of emphasis or clarity, but it’s not required.

Why is it “cumpre” and not something like “alcança” or “consegue”?

All of these verbs are possible but have slightly different nuances:

cumprir um objetivo – to fulfil/meet a goal (do what was planned/expected)
alcançar um objetivo – to reach a goal (often with the idea of effort, “getting there”)
conseguir um objetivo – to manage to achieve a goal (focus on success after difficulty)

So:

cumpre o seu objetivo – she fulfils her goal (she does what she set out to do).
alcança o seu objetivo – she reaches her goal.
consegue atingir o seu objetivo – she manages to achieve her goal.

In your sentence, “cumpre” is in the present indicative, 3rd person singular of cumprir (ela cumpre). It matches a habitual action: when she fulfils her goal.

Why is it “cumpre o seu objetivo” and not “cumpre seu objetivo”?

In European Portuguese, it’s normal to keep the definite article before a possessive:

o seu objetivo – her/his goal
a sua casa – her/his house

Saying “cumpre seu objetivo” (without “o”) is:

common and natural in Brazilian Portuguese,
less typical in European Portuguese, where “cumpre o seu objetivo” is the standard everyday form.

So in Portugal, the pattern is usually:

article + possessive + noun → o seu objetivo, a sua ideia, os seus amigos, etc.

Does “seu objetivo” mean “her goal” or “his goal” here? Isn’t that ambiguous?

Grammatically, “seu” in Portuguese can mean:

his
her
its
your (formal, singular)
your (plural, vocês’)

So “o seu objetivo” is inherently ambiguous without context. In this sentence, context tells us that it refers to “a minha irmã” → her goal.

In spoken European Portuguese, this type of ambiguity is usually resolved by context and is not a big problem.

When speakers want to be very clear, they can say:

“o objetivo dela” – her goal
“o objetivo dele” – his goal

So you could also say:

“...quando a minha irmã cumpre o objetivo dela.” – when my sister fulfils her goal.

What is the difference between “o seu objetivo” and “o objetivo dela”?

Both can mean “her goal”, but there is a nuance:

o seu objetivo
- more formal/neutral/written style,
- matches the possessive pronoun pattern (seu/sua/seus/suas),
- can be ambiguous (his/her/your).
o objetivo dela
- very clear: “her goal” only,
- often sounds more colloquial and explicit,
- used a lot in speech, especially when ambiguity is possible.

In this specific sentence, both:

“cumpre o seu objetivo”
“cumpre o objetivo dela”

are correct. The original with “o seu objetivo” is slightly more neutral/formal.

Why is it “quando a minha irmã cumpre” and not a subjunctive form like “quando a minha irmã cumprir”?

The choice depends on the time reference and meaning of the “quando” clause.

Habitual/general situation → present indicative:
- “Eu fico orgulhoso quando a minha irmã cumpre o seu objetivo.”
  = Every time she fulfils her goal, I become proud.
  This describes a repeated pattern, so “cumpre” (present indicative) is correct.
Future, one-time event → often future subjunctive after “quando”:
- “Ficarei orgulhoso quando a minha irmã cumprir o seu objetivo.”
  = I will be proud when my sister fulfils her goal (in the future).

So:

cumpre (indicative) – for general, habitual actions.
cumprir (future subjunctive form: quando ela cumprir) – for a specific future event that has not happened yet.

Can I say “Eu fico orgulhoso da minha irmã” instead of using the whole clause with “quando…”?

You can, but it doesn’t mean the same thing.

“Eu fico orgulhoso quando a minha irmã cumpre o seu objetivo.”
– I become proud when she fulfils her goal (the pride is triggered by that event).
“Eu fico orgulhoso da minha irmã.”
– I (become/get) proud of my sister (more general pride in her, not necessarily tied to a specific moment or action).

Also note:

With orgulhoso, you normally use the preposition de:
- orgulhoso de alguém / de algo – proud of someone / something
  Example:
- “Estou muito orgulhoso da minha irmã.” – I’m very proud of my sister.

In your original sentence, instead of a “de + noun” complement, we have a “quando” clause that explains under what condition you feel proud.