Complex Sentences | Portuguese (Portugal) Grammar

A complex sentence (frase complexa) joins at least one main clause with one or more subordinate clauses. The main clause could stand alone as a sentence; the subordinate clause cannot — it depends on the main clause to be complete. This dependency is signalled in Portuguese by a subordinator (a conjunction like que, quando, se, porque, embora) or by a relative pronoun (que, quem, o qual, cujo). Learning to recognise and build complex sentences is the jump from writing "I arrived. I called her." to writing "When I arrived, I called her because I had good news" — the difference between survival Portuguese and fluent Portuguese.

Main clause vs. subordinate clause

Every complex sentence has two building blocks: an oração principal (main clause) and one or more orações subordinadas (subordinate clauses). The main clause carries the core assertion; the subordinate clause fills a grammatical role inside it — subject, object, modifier, or adverbial — just as a single word or phrase would.

Eu sei que ela chega amanhã.

I know that she arrives tomorrow.

Here Eu sei is the main clause and que ela chega amanhã is a subordinate clause functioning as the direct object of sei — exactly where a noun like a verdade could go (Eu sei a verdade).

O livro que me emprestaste é excelente.

The book you lent me is excellent.

The main clause is O livro é excelente; que me emprestaste is a relative clause modifying livro, doing the work of an adjective.

Quando chegares a casa, liga-me.

When you get home, call me.

Liga-me is the main clause (a complete imperative); quando chegares a casa is an adverbial clause of time telling us when to call.

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A quick test: can the clause stand alone as a sentence? If yes, it's a main (independent) clause. If it needs a conjunction or relative pronoun to make sense, it's subordinate.

Subordinators: the glue of complex sentences

Portuguese subordinators fall into a few major groups. Memorise this list — it will appear everywhere in reading, writing, and listening:

Type	Common subordinators	What they introduce
Completive	que, se	Noun clauses (object of say, think, know, ask)
Time	quando, enquanto, assim que, logo que, antes que, depois que, até que	When the action happens
Cause	porque, pois, visto que, já que, como	Why the action happens
Condition	se, caso, a menos que, desde que	Under what condition
Concession	embora, ainda que, mesmo que, apesar de que	In spite of what
Purpose	para que, a fim de que	In order to / so that
Result	tão... que, de tal modo que, de maneira que	So... that (consequence)
Manner	como, conforme, segundo	How / according to how
Comparison	como, do que, tal como	Compared to

Some of these — especially embora, para que, a menos que, até que, antes que — require the subjunctive in the subordinate clause. We flag this below and in the dedicated mood pages, but treat it as a fact of the subordinator, not of the sentence meaning.

Type 1: Noun clauses (orações substantivas)

A noun clause does the job of a noun. Most commonly, it's the direct object of verbs of speech, thought, or perception: dizer, saber, pensar, achar, ouvir, ver, perceber. It typically begins with que (that) or, for yes/no reported questions, se (whether/if).

Ela disse que o comboio está atrasado.

She said that the train is late.

Não sei se ele vem hoje.

I don't know whether he's coming today.

Acho que vai chover.

I think it's going to rain.

Ouvi que fecharam aquele café na Baixa.

I heard they closed that café downtown.

Noun clauses can also be subjects of the main verb. This is more literary, but common after impersonal expressions like é importante, é verdade, parece, convém:

É importante que estudes para o exame.

It's important that you study for the exam.

Parece que ninguém reparou.

It seems nobody noticed.

Notice that é importante que triggers the subjunctive (estudes, not estudas), while parece que takes the indicative (reparou). Subordinators and main-clause verbs together determine mood — never guess from the subordinator alone.

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When English lets you drop "that" — "She said he was late" — Portuguese almost never lets you drop que. Leaving out que is one of the most recognisable anglicisms in a learner's writing.

Type 2: Adjective clauses (orações adjetivas, also called relative clauses)

An adjective clause modifies a noun, just as an adjective would. It's introduced by a relative pronoun — most often que, sometimes quem, o qual, cujo, onde. The noun being modified is called the antecedent.

A casa que comprámos precisa de obras.

The house we bought needs renovations.

A senhora que mora ao lado é professora.

The lady who lives next door is a teacher.

Este é o restaurante onde jantámos ontem.

This is the restaurant where we had dinner yesterday.

O colega com quem trabalho vai reformar-se.

The colleague I work with is going to retire.

Relative clauses come in two flavours — restrictive and non-restrictive — which behave slightly differently in punctuation and meaning. We unpack them on the dedicated relative-clauses pages; here, just notice that the relative pronoun plays a role inside the subordinate clause (subject of mora, object of comprámos, object of the preposition com), while also linking the clause to the antecedent outside.

Type 3: Adverbial clauses (orações adverbiais)

An adverbial clause modifies the main verb the way an adverb would — telling us when, why, how, under what condition, in spite of what. Adverbial clauses are where Portuguese grammar gets genuinely rich, because each type of adverbial triggers its own subordinators and often its own mood.

Clauses of time

Quando chegarmos, já deve estar escuro.

When we arrive, it'll already be dark.

Enquanto fazes o jantar, eu ponho a mesa.

While you make dinner, I'll set the table.

Assim que souber alguma coisa, aviso-te.

As soon as I know something, I'll let you know.

Time clauses referring to the future take the future subjunctive (chegarmos, souber), not the indicative — one of the clearest grammatical differences between English and Portuguese.

Clauses of cause

Não fui ao trabalho porque estava doente.

I didn't go to work because I was sick.

Como não tinha tempo, não lhe respondi.

Since I didn't have time, I didn't reply to him.

Porque and como both mean "because," but como typically opens the sentence and presents the cause as already known or shared information.

Clauses of condition

Se tiveres tempo, passa por cá.

If you have time, drop by.

Caso haja problemas, liga-me.

In case there are problems, call me.

Clauses of concession

Embora esteja cansado, vou contigo.

Although I'm tired, I'll go with you.

Mesmo que chova, o jogo realiza-se.

Even if it rains, the match will be held.

Embora and mesmo que both require the subjunctive — they mark the content of the clause as not-quite-asserted, something you concede rather than claim.

Clauses of purpose

Falei devagar para que todos percebessem.

I spoke slowly so that everyone would understand.

Deixei a janela aberta para que o gato entrasse.

I left the window open so the cat could come in.

Para que also requires the subjunctive.

Clauses of result

Estava tão cansada que adormeci no sofá.

I was so tired that I fell asleep on the sofa.

Gritei de tal modo que todos se viraram.

I shouted in such a way that everyone turned around.

Clauses of manner

Fiz o bolo como a minha avó me ensinou.

I made the cake the way my grandmother taught me.

Position of subordinate clauses

Portuguese is flexible about where the subordinate clause sits. An adverbial clause can come before or after the main clause; a noun clause almost always follows the verb whose object it is; a relative clause almost always follows its antecedent.

Se calhar, fico em casa hoje.

Maybe I'll stay home today.

Fico em casa hoje se calhar.

I'll stay home today if it happens to be the case.

Both are grammatical. A fronted adverbial clause (Se calhar, ...) is generally separated from the main clause by a comma; a trailing one (..., se calhar) usually takes a comma too, though shorter clauses can do without. In speech, the pause does the work of the written comma.

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The rhetorical effect shifts with the order. Embora estivesse cansado, fui emphasises the concession; Fui, embora estivesse cansado emphasises the action. Use order to highlight what matters.

Clitic placement in complex sentences

Subordinate clauses are one of the biggest proclisis triggers in European Portuguese: the object pronoun hops in front of the verb inside the subordinate clause, even when enclisis would be the default in a main clause. This is one of the signature features that distinguishes EP from Brazilian Portuguese.

Vi-o ontem.

I saw him yesterday. (main clause — enclisis)

Ela disse que o viu ontem.

She said she saw him yesterday. (subordinate — proclisis)

Quando me ligares, atendo.

When you call me, I'll pick up.

O rapaz que te cumprimentou é meu primo.

The boy who said hi to you is my cousin.

This proclisis-in-subordinates pattern is automatic; you don't need to think about whether the clause is relative, adverbial, or completive. If it's subordinate, the clitic goes in front of the verb.

Stacking subordinate clauses

Real Portuguese stacks subordinate clauses inside subordinate clauses. A sentence might have three or four layers of subordination. Reading dense Portuguese is largely a matter of tracking these layers.

Disse-me que soube pelo Pedro que a reunião, que estava marcada para sexta, foi adiada.

He told me he found out from Pedro that the meeting, which was scheduled for Friday, was postponed.

Breaking this down:

Main clause: Disse-me
First subordinate (noun clause, object of disse): que soube pelo Pedro (que...)
Second subordinate (noun clause, object of soube): que a reunião (...) foi adiada
Third subordinate (relative clause modifying reunião): que estava marcada para sexta

This is normal written Portuguese — journalism, legal texts, and conversational storytelling all do it. Being able to unpack such sentences on the fly is a major B1–B2 milestone.

Mood in subordinate clauses

A complex sentence forces you to decide: indicative or subjunctive in the subordinate clause? The decision is driven by the subordinator and by the main-clause verb. A short list to remember:

Always subjunctive: embora, ainda que, mesmo que, para que, a menos que, antes que, até que, caso
Future subjunctive after: quando, enquanto, assim que, logo que, depois que, sempre que, se (referring to future)
Subjunctive after main verbs of: wish (querer que, desejar que), emotion (gostar que, ter pena que), doubt (duvidar que, não acreditar que), necessity (é preciso que, convém que)
Indicative after main verbs of: knowledge (saber que), certainty (é certo que, é verdade que), direct perception (vi que, ouvi que), straightforward reporting (disse que, contou que)

Quero que venhas à festa.

I want you to come to the party. (subjunctive after querer que)

Sei que vens à festa.

I know you're coming to the party. (indicative after saber que)

The mood difference is semantic: quero que venhas is about your coming as a desired-but-unrealised event; sei que vens asserts it as a known fact.

Common Mistakes

❌ Ela disse ela está cansada.

Incorrect — missing que before the subordinate clause.

✅ Ela disse que está cansada.

She said she's tired.

English happily drops that before a noun clause; Portuguese does not. Forgetting que is the single most frequent anglicism in learner writing.

❌ Quando chegas, liga-me.

Incorrect — indicative used for a future event.

✅ Quando chegares, liga-me.

When you arrive, call me.

For future reference, quando takes the future subjunctive (chegares), not the present indicative. English uses the present to refer to a future event ("when you arrive"), but Portuguese does not.

❌ Ela disse que viu-me ontem.

Incorrect — enclisis inside a subordinate clause.

✅ Ela disse que me viu ontem.

She said she saw me yesterday.

Inside a que-clause, EP requires proclisis: me viu, not viu-me. Brazilian Portuguese tolerates either; European Portuguese does not.

❌ Embora está frio, vou sair.

Incorrect — embora requires the subjunctive.

✅ Embora esteja frio, vou sair.

Although it's cold, I'll go out.

❌ Não fui porque que estava doente.

Incorrect — porque does not combine with que.

✅ Não fui porque estava doente.

I didn't go because I was sick.

Learners sometimes try to stack porque que by analogy with é que, but porque already contains the subordinating function; adding que is ungrammatical.

Key Takeaways

A complex sentence = one main clause + at least one subordinate clause.
Subordinate clauses come in three functional types: noun (like a noun), adjective (modifies a noun), adverbial (modifies the verb).
Each subordinator has its own mood requirements — know the list.
Subordinate clauses trigger proclisis in EP — clitics hop in front of the verb.
Never drop que in Portuguese where English would drop "that."
Real Portuguese stacks subordinate clauses several layers deep; learn to read them in layers.