50. The following stems in -ero-, in which e belongs to the stem, retain the e throughout and are declined like puer (§ 47).
|adulter adulterer||gener son-in-law||puer boy|
|socer father-in-law||vesper evening||Līber Bacchus|
Also, the adjective līber (free) of which līberī (children) is the plural (§ 111.a), and compounds in -fer and -ger (stem fero-, gero-).
lūcifer morning star
a. An old nominative socerus occurs. So vocative puere (boy) as if from †puerus (regularly puer).
b.Vir (man) has genitive virī; the adjective satur (sated) has saturī; vesper (evening) has ablative vespere (locative vesperī in the evening).
c. Mulciber (Vulcan) has -berī and -brī in the genitive. The names Hibēr and Celtibēr retain ē throughout.
51. The following, not having e in the stem, insert it in the nominative singular and are declined like ager (§ 47).
|ager field (stem agro-)||culter knife|
|aper boar||faber smith|
|arbiter judge||fiber beaver|
|auster south wind||liber book|
|cancer crab||magister master|
|caper goat||minister servant|
|coluber snake||oleaster wild olive|
|conger sea eel||onager (-grus) wild ass|
|scomber (-brus) mackerel|