Ordinal Numbers

A Portuguese ordinal number (numeral ordinal) tells you the position of something in a sequence — first, second, third — rather than how many things there are. Unlike English ordinals, which are invariable (the first house, the first houses), Portuguese ordinals behave like adjectives: they agree in gender and number with the noun they modify. O primeiro filho, a primeira filha, os primeiros filhos, as primeiras filhas. Get the agreement wrong and the sentence sounds off the way the firsts house would in English.

This page covers the full series from primeiro to milionésimo, the agreement rules, the abbreviations you will see in Portuguese texts (1.º, 1.ª), and — just as importantly — the places where ordinals are theoretically correct but everyday Portuguese reaches for a cardinal instead. Centuries are século vinte, not século vigésimo, even though the latter is grammatically faultless.

The first ten

These are the ones you will use constantly. Memorize all ten in both genders.

Eleventh to twentieth

Past the tenth, ordinals are formed by juxtaposing décimo with the next ordinal. There is no e (and) between them — unlike cardinals, which do take e. So it is décimo primeiro, never décimo e primeiro.

Notice that both halves agree. If the noun is feminine, both décima and primeira take the feminine form. This is one of the harder things to remember at speed.

The tens: 20th to 100th

These follow a Latin pattern that has to be memorized. They are recognizably similar to the cardinals but with their own stems.

The cardinal-ordinal pairing is opaque in Portuguese: there is no transparent rule by which cinquenta (50) gives you quinquagésimo. These are inherited as discrete forms from Latin (quinquagesimus), and you simply learn them.

Compound ordinals: 21st, 33rd, 154th

To form ordinals like 21st, 33rd, 154th, you simply juxtapose: vigésimo primeiro, trigésimo terceiro, centésimo quinquagésimo quarto. No e. Both (or all three) elements agree in gender and number.

You can already see why everyday Portuguese drops these for cardinals once the numbers get long. Saying centésima quinquagésima quarta aloud is a mouthful; saying cento e cinquenta e quatro is much smoother. We come back to this below.

The hundreds and beyond

The hundred-ordinals exist but are markedly literary. In ordinary speech, Portuguese substitutes a cardinal almost as soon as the number rises above 100.

Agreement: the rule you cannot break

Ordinals agree in gender and number with the noun they modify. This is the single most important point on this page, and the one English speakers most often slip up on, because English ordinals are invariable.

In compound ordinals, both elements agree.

Position: before the noun (usually)

Like most adjectives in Portuguese, ordinals normally precede the noun: o primeiro filho, a terceira porta, a vigésima edição. They follow the noun only in a handful of marked contexts:

• Royal numbering (always after): D. João I, D. Manuel II.
• Chapter and page references (after, with or without ordinal): capítulo primeiro or capítulo um.
• Emphatic or stylized speech: o filho primeiro (rare; literary).

Royal numbering: a special case

Portuguese kings, queens, popes, and emperors take ordinal numbers after the name, written in Roman numerals but read aloud as ordinals up to ten and as cardinals from eleven onwards (because the ordinal forms get unwieldy).

The cutoff for switching to cardinals is around X (ten) or sometimes XII; usage varies. Luís catorze de França is far more common in Portuguese than Luís décimo quarto. Bento décimo sexto would sound oddly bookish; Bento dezasseis is what you hear on the news.

Centuries: cardinals, not ordinals

A point where Portuguese diverges from English habit: centuries are normally read as cardinals, not as ordinals. The Roman numeral XX in século XX is read século vinte, not século vigésimo. The ordinal reading is grammatically possible but sounds bookish or archaic.

Floors and addresses

Floor numbers in buildings are traditionally given as ordinals: primeiro andar, segundo andar, terceiro andar. Increasingly, in casual speech and some signage, you hear cardinals: andar três. Both are understood; the ordinal is the more formal and traditional choice.

Street numbers themselves are always cardinals:

Dates: only the first of the month is ordinal

This is the trick that most learners miss. In European Portuguese, only the first of the month is normally read as an ordinal — and even there, the cardinal is increasingly common. Every other day uses the cardinal.

For more on dates, see the dates and time page.

Abbreviations: 1.º, 1.ª, 1º, 1ª

In writing, ordinals are abbreviated with a superscript letter matching the gender of the noun: º for masculine, ª for feminine. The traditional Portuguese style places a period before the superscript: 1.º andar, 1.ª edição. Increasingly common (especially in informal contexts and on phones) is the version without the period: 1º andar, 1ª edição. Both are seen in print; the period is slightly more conservative and is the form recommended by the Acordo Ortográfico.

When ordinals get replaced by cardinals

A practical summary of where Portuguese prefers cardinals even though ordinals would be technically correct:

• Centuries: século vinte, not século vigésimo.
• Royals from XI onwards: Luís catorze, not Luís décimo quarto.
• Most days of the month: o quinze de março, not o décimo quinto.
• High edition numbers: a edição cento e vinte, not a centésima vigésima edição.
• Page and chapter references (often, in casual speech): página vinte, capítulo cinco.

The general principle: the higher the number, the more likely Portuguese drops the ordinal. Up to ten, ordinals are everywhere. From eleven to twenty, they are still common. Beyond twenty, cardinals creep in. By the hundreds, ordinals survive only in very formal contexts.

Common mistakes

Key takeaways

• Portuguese ordinals agree in gender and number with the noun they modify: primeiro / primeira / primeiros / primeiras.
• The first ten (primeiro through décimo) are everyday vocabulary; learn them cold.
• Compound ordinals (11th, 21st, etc.) are formed by juxtaposition without e: décimo primeiro, vigésimo terceiro. All elements agree.
• The tens (vigésimo, trigésimo, quadragésimo...) are inherited Latin forms with no transparent rule — memorize them.
• Hundreds-ordinals (ducentésimo and up) are technically correct but rarely used in modern speech.
• Centuries in PT-PT are read as cardinals: século vinte, not século vigésimo.
• Royal numbering uses ordinals up to about X, then switches to cardinals: D. João I (primeiro) but Luís XIV (catorze).
• Dates: only the first of the month is normally ordinal (o primeiro de maio); all others are cardinals (o dois de maio, o vinte e cinco de abril).
• Abbreviations use the superscript º (masculine) or ª (feminine), traditionally with a period before: 1.º, 1.ª.