Silent consonants

Silent consonants are the letters once written for etymological reasons but no longer pronounced — chiefly c and p in clusters such as -cç-, -ct-, -pç- and -pt-. Words like acção (“action”), director (“director”), óptimo (“optimal”) or baptismo (“baptism”) preserved, in the older spelling, letters that the spoken language had long abandoned. The 1990 Orthographic Agreement deletes those letters when they are genuinely inaudible, bringing the writing closer to actual pronunciation.

Where they came from

These consonants are a Latin inheritance: ACTIONEM yielded acção, OPTIMUM yielded óptimo, BAPTISMUM yielded baptismo. For centuries the Portuguese spelling tradition — etymological in spirit — kept them out of respect for the Latin form, even after their articulation had vanished from ordinary speech. The republican reform of 1911 and the Luso-Brazilian convention of 1945 simplified spelling greatly, but the 1945 text in force in Portugal chose to retain many of these silent consonants, whereas Brazil had already dropped them in its 1943 formulary. Hence one of the most visible spelling differences between the two traditions across the twentieth century.

The 1990 rule

The Agreement’s principle is simple and phonetic: delete the consonant that is not pronounced; keep the one that is. The decision is not etymological but articulatory — it turns on whether the letter has, or lacks, a sounded realisation in educated usage.

The deletion affects dozens of everyday words. Note that only one consonant is ever dropped — the silent one: in espectáculo the first c was unsounded and the second was not, giving espetáculo.

Before 1990	After 1990	Pronunciation
acção	*ação* (action)	[ɐˈsɐ̃w̃]
colecção	*coleção* (collection)	[kulɨˈsɐ̃w̃]
activo	*ativo* (active)	[ɐˈtivu]
exacto	*exato* (exact)	[iˈzatu]
adoptar	*adotar* (to adopt)	[ɐduˈtaɾ]
óptimo	*ótimo* (optimal)	[ˈɔtimu]

The ones that stay

The Agreement does not remove etymological c and p when they are in fact articulated. So facto (“fact”), pacto (“pact”), rapto (“abduction”), apto (“apt”), núpcias (“nuptials”), erupção (“eruption”), convicto (“convinced”), ficção (“fiction”) and bactéria (“bacterium”) keep the consonant: it is heard. This is a frequently misunderstood point — the Agreement did not “cut every c and p”, only those that had already gone silent.

This yields a useful distinction that European Portuguese preserves: facto (“fact, event”) [ˈfaktu] is not confused with fato (“suit”; in Brazil also “fact”) [ˈfatu] .

Double spellings

For a fringe of words the consonant is pronounced in one educated accent and not in another, within the Portuguese-speaking world itself. In such cases the Agreement admits a double spelling, validating both forms — for instance sumptuoso or suntuoso (“sumptuous”), peremptório or perentório (“peremptory”). These are not errors but legitimate alternatives reflecting real variation in pronunciation.

The vowel objection

The most consistent criticism of the deletions notes that the silent consonant sometimes did a job: it signalled that the preceding vowel was open. In óptimo, the p “warned” that the stressed o was [ɔ] rather than [o] . Once the letter goes, that visual cue disappears, and words like ótimo or fator now rely on the accent or on the reader’s habit for the right vowel quality. Defenders of the Agreement reply that Portuguese spelling is fundamentally phonological, and that keeping inaudible letters for etymology alone runs against that principle.

What to take away

Silent consonants were graphic fossils of Latin. The 1990 Agreement cleared away those the ear no longer recognised — ação, ótimo, diretor — and kept those that still sound — facto, pacto, ficção. When in doubt, a practical rule serves: say the word carefully; if you hear the c or p, write it; if you do not, leave it out — save for the double spellings, where the language itself hesitates.