Good spelling is part memory, part judgment. Proper spelling techniques should be memorized and practiced, but writers should judge their own abilities and look up unknown words. The English language contains numerous exceptions for every rule, so a good dictionary and thesaurus are essential. Look up words that are unfamiliar, that you do not use often, or that contain a spelling rule that you do not know completely. Some of the more common spelling errors occur in creating plurals, adding suffixes, and with double consonant or vowel constructions.
Adding -s or -es to a word is
the most common way to create a plural, but there
are a variety of other situations in which writers
must use other letters to create plurals. Add
-s to most words that end in "hard" consonant
sounds, including "hard" -ch (sounding
like k): hats, teams, computers, bites, tapes,
stomachs Add -es to words that end in -s,
-sh, -x, -z, or "soft" -ch (sounding like
march): lenses, taxes, marches
Add -s if a vowel precedes the -o:
videos, neutrinos, cameos.
There are no set rules for these words. You will
have to memorize them or look them up. Some -f
or -fe words are made plural by adding
-s: beliefs, roofs, chiefs. Others require the
writer to change the -f or -fe to
-ves: life - lives, leaf - leaves.
Some words are changed internally to create plurals:
foot - feet, goose - geese, mouse - mice.
Some words retain the same spelling for both
singular and plural: deer, elk, fish.