Ontem

Ontem is a time adverb in Portuguese that designates the day before today. It is used in both Brazilian Portuguese and European Portuguese to refer to actions, events, or times that occurred on the previous day. It can stand alone or be combined with phrases indicating part of the day, for example ontem à noite (last night) and ontem de manhã (yesterday morning).

Grammatical notes: Ontem is invariable and does not encode gender or number. It typically modifies a verb or sentence to set the temporal frame, as in "O que você fez ontem?" or "Ontem foi um dia longo." It contrasts with hoje (today) and amanhã (tomorrow). In formal writing, it commonly appears in prose and narration, including descriptive or recounting passages.

Etymology: The precise origin of ontem is not definitively settled. It is a native word in the Iberian Romance languages, with related forms attested in Galician (onte). The development from early forms in Old Portuguese is the subject of linguistic study.

See also: Portuguese grammar, time adverbs, past-tense constructions.