Learn Hardcore Portuguese (Portugal): Eu recuso o convite porque estou cansado. - I refuse the invitation because I am tired.

Including Eu adds a bit of emphasis, like “I refuse the invitation because I’m tired (not someone else)” or “Me, I refuse it…”. In normal, neutral speech, many speakers would omit Eu here.

Why do we need the article o in o convite? Could I just say recuso convite?

In this sentence, you’re talking about a specific invitation (the one you’ve just been offered), so in Portuguese you normally use the definite article:

o convite = the invitation

Saying recuso convite without o sounds wrong or, at best, very unnatural in European Portuguese in this context.

You can omit the article mainly:

in some set expressions or titles (e.g. Convite para a festa on a card),
with certain abstract or uncountable nouns in specific contexts.

But with a concrete, specific object like this, you should say o convite.

What’s the nuance of recusar compared with verbs like rejeitar or negar?

All three can be translated as some kind of “refuse/reject/deny”, but they’re used differently:

recusar = to refuse / decline an offer, request, invitation, etc.
- Eu recuso o convite. – I decline the invitation.
- Ela recusou o pedido. – She refused the request.
rejeitar = to reject something more strongly or categorically (ideas, proposals, people, offers).
- Rejeitei a proposta. – I rejected the proposal.
- Feels a bit stronger or more formal than recusar with an invitation.
negar = to deny (say something is not true) or refuse to give something.
- Ele negou o crime. – He denied the crime.
- Negaram-lhe ajuda. – They refused him help.

For an invitation, recusar o convite is the most natural choice in European Portuguese.

I’ve seen recusar-se a. Why don’t we say Eu recuso-me ao convite or something similar?

Recusar has two common patterns:

recusar algo (transitive verb)
- Eu recuso o convite. – I refuse the invitation. (your sentence)
recusar-se a fazer algo (reflexive + preposition)
- Eu recuso-me a ir. – I refuse to go. / I won’t go.

So:

If you refuse a thing (invitation, request, proposal), you normally say recusar + object.
If you refuse to do an action, you normally use recusar-se a + infinitive.

Recuso-me ao convite is not idiomatic; you’d either:

Recuso o convite. (refuse the invitation)
or
Recuso-me a aceitar o convite. (refuse to accept the invitation).

Can I say porque eu estou cansado instead of porque estou cansado?

Yes, both are correct:

…porque estou cansado.
…porque eu estou cansado.

The version without eu is more neutral and more common in everyday speech.

Adding eu gives a bit of emphasis, like:

“…because I am tired (not for some other reason / not someone else).”

Grammatically, both are fine in European Portuguese.

Why is it porque (one word) here and not por que, porquê, or por quê?

In this sentence, porque is a conjunction meaning “because”. As a rule:

porque (one word)
- used as “because” to introduce a reason:
- Recuso o convite porque estou cansado.

The others are used in questions or noun uses:

por que – “why” / “for what (reason)” in direct or indirect questions:
- Por que recusas o convite? – Why do you refuse the invitation?
- Não sei por que recusas. – I don’t know why you refuse.
porquê – a noun meaning “the reason / the why”:
- Ninguém entende o porquê da recusa. – Nobody understands the reason for the refusal.
por quê – in Brazilian Portuguese, used at the end of a sentence or before punctuation; in European Portuguese spelling, you’ll normally just see porquê in those positions.

In your sentence, you’re giving a reason, so it must be porque = “because”.

Could I use pois or já que instead of porque here?

Yes, but with slightly different feel:

pois – “since/as/because”, more formal or literary, and often comes after the verb:
- Recuso o convite, pois estou cansado.
  Sounds a bit more formal or written than porque.
já que – “since / given that”:
- Recuso o convite, já que estou cansado.
  This makes the reason feel very obvious or already known.

Porque is the most neutral and common choice in everyday European Portuguese.

Why do we say estou cansado and not sou cansado?

In Portuguese:

estar is used for temporary states or conditions:
- Estou cansado. – I’m (currently) tired.
- Estou doente. – I’m ill (at the moment).
ser is used for more permanent or characteristic traits:
- Sou alto. – I am tall.
- Sou simpático. – I am nice (by nature).

So estou cansado means you’re tired right now (or in this period), which is exactly what you want as the reason for refusing.

Sou cansado would sound like “I’m a tiring person / easily tired by nature”, which is not what is meant here.

Does cansado change if the speaker is a woman, or if there are several people?

Yes, cansado agrees in gender and number with the subject:

1 man: Estou cansado.
1 woman: Estou cansada.
Group of men / mixed group: Estamos cansados.
Group of women only: Estamos cansadas.

So a woman would say:

Eu recuso o convite porque estou cansada.

Is the word order fixed, or could I move things around, like Recuso, porque estou cansado, o convite?

The natural word order in European Portuguese here is:

[Eu] recuso o convite porque estou cansado.
(Subject) – (verb) – (object) – (reason clause)

Some variations are possible but marked:

Recuso o convite, porque estou cansado. – just adds a comma, same order, very normal.
Porque estou cansado, recuso o convite. – also correct, slightly more formal/emphatic (fronts the reason).

But:

Recuso, porque estou cansado, o convite sounds wrong.
Recuso o convite porque cansado estou is highly unusual/poetic.

So for everyday speech, stick to:

Recuso o convite porque estou cansado.

How should I pronounce recuso and convite in European Portuguese?

Approximate European Portuguese pronunciation:

recuso: /ʁɨˈkuzu/
- ʁ – back-of-the-throat “r” (like French r).
- ɨ – very reduced, almost like an unstressed “uh”.
- Stress on the cu: re-CU-so.
convite: /kõˈvit(ɨ)/
- con-: nasal vowel /õ/, like on in French.
- vi: like “vee”.
- Final -te often has a very weak vowel /ɨ/ or is almost just /t/ depending on the speaker.
- Stress on vi: con-VI-te.

Spoken at normal speed by a European Portuguese speaker, the full sentence would sound like something close to:

[ɨw ʁɨˈkuzu u kõˈvit(ɨ) puʁˈke ɨʃˈto kɐ̃ˈsadʊ]
(with many unstressed vowels reduced and a uvular r).