Alex Notes
The Infinitive, Stem and Spelling Changes
The Infinitive
In English, to run is the infinitive
form of the verb run. In the sentence
He runs, the word runs is the
the form of run conjugated in the
present tense, indicative mode,
third person singular. The infinitive form
of a verb is the form found in a dictionary.
In the preceding example, run would be the
main entry in a dictionary, not runs or ran.
In their infinitive form, all verbs in
Spanish end in -ar, -er, or -ir.
For instance, correr is the Spanish infinitive
corresponding to the English infinitive to run.
Verbs in Spanish are classified according to the ending of their infinitive form. Within each type, ‘regular’ verbs are conjugated the same way, while ‘irregular’ verbs deviate. Some irregular verbs within a type may be conjugated the same way as each other, thus creating various irregular subtypes within the three infinitive types.
The Stem
The stem of a Spanish verb is what remains after dropping the infinitive suffix. For example:
hablar / habl-
correr / corr-
venir / ven-
Many formation rules for a verb are given in terms of its stem.
Stem Changing Verbs
Some verbs undergo changes to their stem. When a rule is given in terms of a verb’s stem, these changes are assumed.
Verbs like querer and encontrar
There are no -ir verbs in this category
Verbs like sentir(se) and dormir
Only -ir verbs are in this category.
Verbs like pedir
Only -ir verbs are in this category.