When conjugating a verb ending in -ger, for "nous" the "g" in the stem is kept in order to preserve pronunciation.
When conjugating a verb ending in -cer, for "nous" the "c" becomes "ç" in order to preserve pronunciation.
When conjugating verbs ending in -yer, the "y" becomes an "i" for singular and third person verbs. For verbs ending in -ayer the "y" can be kept or changed to an "i".
For most verbs ending in -eler or -eter, the end constant is doubled before a silent "e". verbs that are an exception are: acheter, deceler, geler, haleter, harceler, modeler, and peler.
An "accent grave" is given if the final syllable of a stem is an e or é.
Aller is an irregular verb.