The Four Kinds of Irregularity
Sort Spanish irregular verbs into stem changes, spelling changes, irregular stems, and suppletive verbs.
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Questions Covered in This Set
11 cards to master
What is a stem change (boot verb)?
A vowel in the last stem syllable shifts when stressed: e→ie, o→ue, e→i, u→ue. It appears in all present forms except nosotros/vosotros, creating the 'boot' shape.
Which stem-changers have a SECOND, weaker change — and where does it show up?
Only -ir stem-changers (e→i, o→u): 3rd-person preterite (pidió, durmió), gerund (pidiendo, durmiendo), the whole imperfect subjunctive (pidiera), and nosotros/vosotros of the present subjunctive (pidamos, durmamos).
Why do -car, -gar, -zar verbs change spelling before 'e'?
To preserve pronunciation — the sound is perfectly regular. c→qu (busqué), g→gu (pagué), z→c (empecé).
Spelling changes before a/o: -ger/-gir, -guir, -cer/-cir after a vowel
g→j (proteger → protejo, proteja); gu→g (seguir → sigo, siga); c→zc (conocer → conozco, conozca).
What is the i → y rule?
Unstressed i between vowels becomes y: leer → leyó, leyeron, leyendo; construir → construyó.
What endings attach to preterite strong stems?
-e, -iste, -o, -imos, -isteis, -ieron — with NO written accents (tuve, tuvo, not tuvé/tuvó).
Name several preterite strong stems.
tener→tuv-, estar→estuv-, poder→pud-, poner→pus-, saber→sup-, hacer→hic- (hizo), querer→quis-, venir→vin-, decir→dij-, traer→traj-, conducir→conduj-.
What happens to strong stems ending in j?
They drop the i in the ellos ending: dijeron, trajeron, condujeron — never 'dijieron'.
Why learn the future stem list only once?
Future and conditional share identical stems (tendr-, pondr-, saldr-, vendr-, podr-, sabr-, habr-, querr-, dir-, har-, cabr-, valdr-), so tendré/tendría, haré/haría — endings never vary.
What is the highest-leverage rule involving the yo form?
The present subjunctive and negative/formal commands are built from the yo form: tengo→tenga, salgo→salga, conozco→conozca.
What is suppletion?
Forms drawn from different historical roots glued into one paradigm (e.g. ir/ser). There is no rule — only memorization — but there are essentially only four such verbs.
