Sous-employer is a french first group verb. So it follow the regular conjugation pattern of the first group like:
aimer.
Follow this link to see all the endings of the conjugation of the first group verbs :
conjugation rules and endings for the first group verbs.
However, although the terminations are perfectly regular, stem can be irregular and have numerous variations.
Sous-employer is conjugated the same way that verbs that end in :
-yer.
Verbs ending in
-yer may transform the stem letter
« y » in
« i » before a silent endings.
It is the case for verbs ending in
-oyer and
-uyer (other than envoyer and renvoyer). They replace the
« y » with an
« i » before an unpronounced
« e », turning the preceding syllable in a diphthong. The prototypical verbs are broyer, noyer, ennuyer.