Rules for writers, Tenth edition - Diana Hacker, Nancy Sommers 2021

Become familiar with the major spelling rules
Spelling
Mechanics

You learned to spell from repeated experience with words in both reading and writing. As you proofread, you may be able to tell if a word doesn’t look quite right. In such cases, the solution is simple: Look up the word in a dictionary.

44a Become familiar with the major spelling rules.

i before e except after c

In general, use i before e except after c and except when sounded like ay, as in neighbor and weigh.

Suffixes

Final silent -e

Generally, drop a final silent -e when adding a suffix that begins with a vowel. Keep the final -e if the suffix begins with a consonant.

Final -y

When adding -s or -d to words ending in -y, ordinarily change -y to -ie when the -y is preceded by a consonant but not when it is preceded by a vowel.

With proper names ending in y, do not change the -y to -ie even if it is preceded by a consonant: the Bradys (the Brady family).

Final consonants

If a final consonant is preceded by a single vowel and the consonant ends a one-syllable word or a stressed syllable, double the consonant when adding a suffix beginning with a vowel.

✵ bet, betting

✵ commit, committed

✵ occur, occurrence

Plurals

-s or -es

Add -s to form the plural of most nouns; add -es to singular nouns ending in -s, -sh, -ch, or -x.

Ordinarily, add -s to nouns ending in -o when the -o is preceded by a vowel. Add -es when the -o is preceded by a consonant.

Other plurals

To form the plural of a hyphenated compound word, add -s to the chief word even if it does not appear at the end.

mother-in-law, mothers-in-law

English words derived from other languages such as Latin, Greek, or French sometimes form the plural as they would in their original language.

✵ chateau, chateaux

✵ criterion, criteria

✵ medium, media