When I say populaire for a boy don't I have to take off the "e"! And for myself since I'm a boy to i add an "e" or don't do nothing at all to chic and mignon.
Some adjectives end in -e whether they are masculine or feminine. That, however, is a good question! Correct = chic and mignon are masculine singular, but the feminine of mignon is mignonne. "chic" is invariable, meaning it's the same form for both masculine and feminine singular. It's also slang for "great!"
Here's a list of other adjectives like "populaire:"
agréable (pleasant)
aimable (kind)
autre (other)
aveugle (blind)
bizarre (peculiar, odd)
brave (brave, fine)
célèbre (famous)
chauve (bald)
coupable (guilty)
difficile (difficult)
drôle (funny, odd)
énorme (enormous)
étrange (strange)
facile (easy)
fidèle (faithful)
gauche (left)
grave (serious, solemn)
honnête (honest, polite)
illustre (illustrious)
inutile (useless)
jaune (yellow)
jeune (young)
juste (just, right)
large (wide) ***fake friend, NOT large!
libre (free)
magnifique (magnificent)
maigre (thin, lean)
malade (sick)
mince (thin, slender)
moderne (modern)
nécessaire (necessary)
pâle (pale)
pauvre (poor)
proche (near)
propre (clean, own) *as in my own book
rapide (fast, rapid)
riche (rich)
rose (pink)
rouge (red)
russe (Russian)
sage (wise, well-balanced)
sale (dirty)
sauvage (wild)
sembable (similar)
sincère (sincere)
timide (timid)
triste (sad)
utile (useful)
vide (empty)
Sra (aka Mme)