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Portuguese (Portugal)

Life in an isolated lighthouse involves constantly watching the sea and the weather.

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When observing these changing conditions from afar, you naturally make assumptions about what is happening out on the water.

### Expressing Probability with "Dever de"

In Portuguese, the verb **dever** often expresses obligation (should/must do something). However, when you want to express a strong deduction or probability based on evidence—like assuming someone "must be" lonely or a ship "must be" English—you use **dever**, followed by the preposition **de**, and an **infinitive** verb.

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This structure is very common when speculating about the harsh coastal weather, such as an incoming gale (**a ventania**).

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### Probability with Continuous Actions

If you are assuming that an action is currently ongoing, you simply combine **dever de** with the continuous aspect (**estar a** + infinitive). 

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### Speculating About Intentions and Future Events

You can also use this periphrasis to speculate about what others want to do, especially when faced with extreme situations like an imminent shipwreck (**o naufrágio**).

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Probability (deve de ser)

adjective

adverb

conjunction

contraction

determiner

interjection

noun

numeral

particle

phrase

prefix

prep

preposition

pron

pronoun

sentence

verb

Demonstratives and the verb to be (isto é, o, a)

Subject pronouns and negation (eu, não)

Yes/no questions and question words (quem, o que)

Plural pronouns, articles, and verbs (somos, são, os, as)

Origin and possession (de, do, da)

Introductions (chamar-se)

Indefinite articles (um, uma, uns, umas)

The verb to be for locations (estar)

Contrasting the two verbs to be (ser vs. estar)

Preposition for locations (em, no, na)

Numbers 0 to 10 (zero, um, dois)

The verb to have (tenho, tem)

Regular -ar verbs (falar, trabalhar)

Regular -er verbs (comer, beber)

Regular -ir verbs (abrir, partir)

My, your, and our (o meu, a nossa)

His, hers, and theirs (dele, dela)

Adjective agreement and placement

Days of the week (segunda-feira)

Months of the year (janeiro)

Counting by tens to 100 (trinta, quarenta...)

Telling time (é uma, são...)

Asking about time (quando, a que horas)

The verb to go (ir)

Prepositions of direction (a, para)

Preposition a contractions (ao, à, aos, às)

Prepositions of place (ao lado de, em frente de...)

Demonstratives (este, esse, aquele)

Contractions with demonstratives (neste, desse, daquele)

Asking which and how many (qual, quanto)

Plurals ending in -ão (-ões, -ãos, -ães)

Plurals ending in consonants (-ns, -is, -es)

The verb to like (gostar de)

The verb to need (precisar de)

The verb to want (querer)

The verb can or may (poder)

Expressing obligation (ter de)

Adverbs of degree (muito, pouco)

Quantifiers (muito, pouco)

Comparatives (mais... do que, menos... do que)

Equality comparisons (tão... como)

The preposition com (comigo, contigo)

Coordinating conjunctions (e, mas, ou, porque)

The preposition por (pelo, pela)

Double negation (nunca, nada, ninguém)

Present continuous (estar a)

Near future (ir)

Past tense of regular -ar verbs

Past tense of regular -er and -ir verbs

Past tense of ser and ir (fui, foi)

Direct object pronouns (me, te, o, a, nos, os, as)

Pronoun placement with negatives and questions

Greetings and courtesy (bom dia, obrigado)

Physical states with ter (ter fome, ter frio)

Asking the way (à direita, sempre em frente)

Colours (vermelho, amarelo, cor-de-rosa)

Money and shopping (custar, a moeda)

Getting around (o motorista, a paragem de autocarro)

Weather and seasons (faz calor, o inverno)

Omitting the subject pronoun

Where things are: ficar (Onde fica...?)

Richer questions: que + noun and é que

Numbers above 100 (cento e vinte, mil)

First-person sound changes (durmo, prefiro)

Advice and ability: dever and saber

Asking why: porquê and porque

When one thing happens: quando-clauses

Here and there: aqui, aí, ali (cá e lá)

Formal and plural possessives: o seu, o vosso

Irregular presents: ver, vir, dar

Present irregulars

Reflexive verbs (me, te, se, nos)

Stem-changing reflexives

Attached object pronouns (-lo, -la, -los, -las)

Nasal attached pronouns (-no, -na, -nos, -nas)

Pronoun placement with adverbs

Past tense of fazer, dizer, and trazer

Past tense of ter, estar, poder, and saber

Past tense of querer and vir

Past tense of ver, dar, and ler

Past tense reflexive verbs (-se)

Time elapsed in the past (há)

Question	Answer
the horizon	o horizonte
dense	denso
I was looking at the horizon when the dense fog arrived.	Eu estava a olhar para o horizonte quando o nevoeiro denso chegou.
He was walking slowly through the dense fog.	Ele estava a caminhar lentamente através do nevoeiro denso.
the lighthouse keeper	o faroleiro
the seagull	a gaivota
The lighthouse keeper has been observing the seagulls.	O faroleiro tem vindo a observar as gaivotas.
must (probability)	dever de
In fact, the lighthouse keeper must be very lonely.	De facto, o faroleiro deve de estar muito sozinho.
the vessel	a embarcação
The vessel must be English.	A embarcação deve de ser inglesa.
The lighthouse illuminates the rock so the vessel does not crash.	O farol ilumina a rocha para a embarcação não bater.
the gale	a ventania
With this gale, the waves must be huge.	Com esta ventania, as ondas devem de estar enormes.
The gale has been growing since dawn.	A ventania tem vindo a crescer desde a madrugada.
to roar	rugir
The dark sea must be roaring.	O mar escuro deve de estar a rugir.
The waves begin to roar from where the storm comes.	As ondas começam a rugir donde vem o temporal.
the shipwreck	o naufrágio
imminent	iminente
The risk of an imminent shipwreck is very high.	O risco de um naufrágio iminente é muito alto.
They must want to avoid the shipwreck.	Eles devem de querer evitar o naufrágio.
The seagulls must be looking for the lighthouse keeper.	As gaivotas devem de estar a procurar o faroleiro.
The lighthouse keeper warned that the storm was imminent.	O faroleiro avisou que o temporal era iminente.
Since the storm is imminent, the vessel must return.	Visto que o temporal é iminente, a embarcação deve de regressar.
distant	longínquo
The distant vessel must be approaching the horizon.	A embarcação longínqua deve de estar a aproximar-se do horizonte.
The fog is so dense that there must be a shipwreck soon.	O nevoeiro está tão denso que deve de haver um naufrágio em breve.
The light shines from that distant country from where the ships arrive.	A luz brilha daquele país longínquo donde chegam os navios.