French stem-changing verbs are conjugated with the same endings as regular -ER verbs but have two different radicals or stems. Stem-changing verbs are sometimes also called boot verbs or shoe verbs, because if you circle the forms that have stem changes in the conjugation table below, the resulting shape looks like a boot or shoe.
All verbs that end in -yer are stem-changing verbs, but there are two different varieties:
- Verbs that end in -ayer (see below) have an optional stem change
- Verbs that end in -oyer and -uyer (see page 2) have a required stem change
-ayer verbs
In the present tense, -ayer verbs have an optional stem change: y changes to i in all forms but nous and vous.
je paie nous payons
tu paies vous payez
il paie ils paient
Or they can be conjugated as regular -ER verbs:
je paye nous payons
tu payes vous payez
il paye ils payent
These two sets of conjugations for -ayer verbs are equally acceptable.
Verb conjugation group
balayer - to sweep
effrayer - to frighten
essayer - to try
payer - to pay
These stem changes are not limited to the present tense; see payer in all tenses or the lesson on -yer verbs in other tenses.
Note: Verbs that end in -oyer and -uyer have the same stem change, but it is required: -oyer and -uyer verbs.
