The noun "familiar" is an enchanted creature, such as a witch's pet. It has the plural familiars.
The adjective familiar (known, recognized) would not have a plural.
You spell it like this F-A-M-I-L-I-E-S
The plural is bridges.
The plural of address is addresses.
The plural of "turkey" is "turkeys."
The plural of cylinder is cylinders.
These are: Mi (my), mío (mine), su (your), suyo (yours), tu (your - familiar), tuyo (yours - familiar), nuestro/a (our), vuestro (your - plural familiar), su (your plural), suyo (yours plural).
The plural way to spell studio is studios.
The plural is hooves.
The plural is cherries.
The plural is cantaloupes.
The plural is resources.
The plural is roses.
The plural is "emeralds."
You spell it like this F-A-M-I-L-I-E-S
The plural is bridges.
Trout is plural
The plural of beach is beaches.