In short

The regular preterite from Lesson 20 is the predictable majority; this lesson is the short list of verbs that break the mould - and they break it precisely because they are the ones you use most. Ser, ir, ter, estar, fazer, dizer, poder, querer, ver, vir, dar, saber, trazer, pôr, haver: you cannot tell a story about yesterday without them. The good news is that there are only fifteen or so, they fall into a couple of tight patterns, and the endings on the tu, nós and eles forms are almost the same across the whole group. What you really have to memorise is the eu and the ele form of each - short, root-stressed shapes like fiz / fez, tive / teve, pude / pôde - and the rest of the row falls into place.

The rule

The strong-preterite pattern

Most of these verbs are “strong”: the stress sits on the stem, not on the ending, which is why the eu and ele forms come out short and usually carry no written accent. Take a special preterite stem and add:

• eu -e, tu -este, ele -e, nós -emos, eles -eram

Look at ter (stem tiv-): tive, tiveste, teve, tivemos, tiveram. The tu, nós and eles rows are perfectly regular on that stem (tiv-este, tiv-emos, tiv-eram); only the eu and ele forms need learning by heart (note the vowel flip tive -> teve). The same skeleton runs through estar (estive, esteve…), poder (pude, pôde…), saber (soube, soube…), haver (houve…), dizer (disse…) and trazer (trouxe…). Learn the pattern once and you have unlocked the tu/nós/eles forms of the entire family.

The verbs whose eu form does not end in -e

Three high-frequency verbs keep the strong tu/nós/eles endings but have an eu form ending in a consonant, and an ele form that either changes only the vowel (fez), matches the eu form exactly (quis), or adds an accent (pôs):

• fazer -> fiz / fez (fizeste, fizemos, fizeram)
• querer -> quis / quis (quiseste, quisemos, quiseram)
• pôr -> pus / pôs (puseste, pusemos, puseram)

The suppletive verbs: ser, ir, dar, ver, vir

A handful of the commonest verbs use forms that come from a different root entirely, so there is nothing to derive - just memorise them.

• ser and ir share one and the same preterite: fui, foste, foi, fomos, foram. Context alone tells the two apart: Fui médico (“I was a doctor”) vs Fui ao médico (“I went to the doctor”).
• dar borrows -er/-ir-style endings: dei, deste, deu, demos, deram.
• ver: vi, viste, viu, vimos, viram.
• vir: vim, vieste, veio, viemos, vieram.

Written accents that mark the past

Two third-person-singular forms carry a circumflex that is not decoration - for pôde it is the only thing separating the past from the present in writing, so it is obligatory:

• poder: pôde (past) vs pode (present) - Ontem não pôde vir / Hoje não pode vir.
• pôr: pôs (past) vs põe (present); the infinitive itself keeps its accent (pôr) to stay apart from the preposition por.

Everything else in the paradigm is accent-free: fez, fui, foi, quis, disse, veio take no written accent at all.

Forms that overlap - let context decide

Because the eu and ele endings are both a bare -e, five verbs have an identical eu and ele form: disse, soube, quis, trouxe, houve. The subject (or the pronoun eu / ele) is what tells you who. And one preterite form clashes with a present one, exactly as in Lesson 20: vimos is both “we saw” (the preterite of ver) and “we come” (the present of vir) - only context, and which verb it belongs to, tells them apart.

Forms & patterns

The core irregulars in full (European Portuguese; você / o senhor / ele share the third-person singular, vocês / eles the plural):

Two quick meaning notes on the table. Haver in the preterite is almost only used in the third person singular houve = “there was / there were” (Houve um problema). And saber in this tense often means “found out / learned”, not “knew”: Soube ontem que ele casou (“I found out yesterday that he got married”).

Examples

Common mistakes

• tu fizestes / tivestes / fostes -> fizeste / tiveste / foste - as with regular verbs (Lesson 20), the tu preterite never ends in -s; adding one is a persistent Spanish-influenced slip.
• ontem ele pode vir -> ontem ele pôde vir - the past third-person of poder takes a circumflex; without it you have written the present pode. The same holds for pôs vs põe.
• Mixing up vir and ver: vim / veio mean “came”, vi / viu mean “saw”. Vi-o na estação (“I saw him at the station”) is not Vim-no.
• eu fazi / dizi / tivi / sabi -> fiz / disse / tive / soube - these are strong preterites, so they do not take the regular -er endings; there is nothing to build, only to remember.
• Reading fui as only “went”: it is equally ser (“was”). A reunião fui longa is wrong for “the meeting was long” only because the subject is third person - it must be A reunião foi longa; but Eu fui professor (“I was a teacher”) is perfectly correct.
• trazi / trouxi -> trouxe - spelled with x, ending in -e, and identical in the eu and ele forms (Eu trouxe / Ele trouxe); the subject shows who brought what.
• nós fomos vs nós formos: the nós preterite of ser/ir is fomos (one r-less, short form); formos is a different tense you meet much later.

Tips

• Drill the eu + ele pair of each verb first (tive/teve, fiz/fez, pude/pôde, pus/pôs, vim/veio, fui/foi). Once those are automatic, the tu/nós/eles rows are the same -este / -emos / -eram endings on the same stem.
• Ser and ir have one preterite between them (fui, foste, foi, fomos, foram) - one of the highest-frequency verb forms in the language, and always sorted out by context.
• The only written accents in the whole set are pôde, pôs (and the infinitive pôr). Everything else - fez, quis, disse, veio, fui - is accent-free.
• Five verbs collapse their eu and ele forms into one shape (disse, soube, quis, trouxe, houve); do not hunt for a separate “he” form - let the subject carry the meaning.
• These fifteen or so verbs cover the overwhelming majority of irregular past forms you will ever need; there is no long tail to fear here, unlike the present tense.
• Watch the look-alike vimos: it is the preterite of ver (“we saw”) but the present of vir (“we come”); the form is identical, so context and the surrounding verb are what disambiguate.