Imperfect Stems

Imperfect stems apply in the imperfect indicative. Only a small set of very common verbs has an Imperfect stem. These use short ending -a, ·as, etc. instead of -aba, ·ía, -abas, ·ías, etc.

Here is a list of model verbs with Imperfect stems:

Model Verbs with Imperfect stems

Verb	Imperfect Stem
ser	er·an
ir	ib·an
ver	veí·an

Imperfect stem reference table

Pronoun	Tense	Ending
yo	Imperfect	a
tú	Imperfect	as
él	Imperfect	a
nosotros	Imperfect	amos
vosotros	Imperfect	ais
ellos	Imperfect	an