names
plurals
preferred plurals

Names
Form plurals of family names that end in "s" by adding "es."

Right:	The Jameses live in Edgewood.
Right:	The James family lives in Edgewood.

Form possessives of proper names that end with "s," "x" and "z" like this:

Right:	Burns's poems
Right:	Marx's theories
Right:	Savitz's holdings

Plural possessives combine the above rules:

Right:	the Jones family's reputation
Right:	The Joneses' reputation

Plurals
Form plurals of the following by adding "s" alone:

Right:	dos and don'ts
Right:	CDs
Right:	M.A.s and Ph.D.s
Right:	The three Rs
Right:	the early 1920s
Right:	several YMCAs
Right:	CODs and IOUs
Right:	in twos and threes

Form plurals of the following by adding 's:

Right:	S's, A's and I's
Right:	x's and o's
Right:	SOS's

Preferred Plurals
alumni, alumnae (women only), alums
appendixes, not appendices
data, not datums
memoranda, not memorandums
millennia, not millenniums
symposia, not symposiums

For plural use of "faculty" and "staff," see Using Tricky Words.