When looking for grammar and usage errors, be on the lookout for easily confused words. These sets of words have similar meanings or spellings. The list below gives some of the more common sets of easily confused words.
a, an: A precedes words beginning with consonants or consonant sounds; an precedes words beginning with vowels or vowel sounds.
affect, effect: Affect is most often a verb; effect is usually a noun. (The experience affected me significantly OR The experience had a significant effect on me.)
amount, number: Amount is used for noncountable sums; number is used with countable nouns.
cite, site: The verb cite credits an author of a quotation, paraphrase, or summary; the noun site is a location.
every day, everyday: Every day is an indefinite adjective modifying a noun; everyday is a one-word adjective implying frequent occurrence. (Our visit to the Minnesota State Fair is an everyday activity during August.)
fewer, less: Fewer is used with a countable noun; less is used with a noncountable noun. (Fewer parents are experiencing stress since the new teacher was hired. Parents are experiencing less stress since the new teacher was hired.)
good, well: Good is always the adjective; well is always the adverb except in cases of health. (She felt well after the surgery.)
implied, inferred: Implied is something a speaker does; inferred is something the listener does after assessing the speaker’s message. (The speaker implied something mysterious, but I inferred the wrong thing.)
irregardless, regardless: Irregardless is nonstandard usage and should be avoided; regardless is the proper usage of the transitional statement.
its, it’s: Its is a possessive case pronoun; it’s is a contraction for it is.
principal, principle: As a noun, principal is an authority figure, often the head of a school; as an adjective, principal means main; the noun principle means idea or tenet. (The principal of the school spoke on the principal meaning of the main principles of the school.)
quote, quotation: Quote is a verb; quotation is a noun.
should of, should have: Should of is improper usage—of is not a helping verb and therefore cannot complete the verb phrase; should have is the proper usage. (He should have driven.)
than, then: Than sets up a comparison; then indicates a reference to a point in time. (When I said that I liked the hat better than the gloves, my sister laughed; then she bought both for me.)
their, there, they’re: Their is the possessive case of the pronoun they; there is the demonstrative pronoun indicating location or place; they’re is a contraction of the words they are.
to lie (to recline), to lay (to place): To lie is the intransitive verb meaning to recline; to lay is the transitive verb meaning to place something. (I lie out in the sun; I lay my towel on the beach.)
unique: Unique is an ultimate superlative; it should not be preceded by adverbs like very or extremely. (The experience was unique.)
who, whom: Who is the subject relative pronoun. (My son, who is a good student, studies hard.) Here, the son is carrying out the action of studying, so the pronoun is a subject pronoun (who). Whom is the object relative pronoun. (My son, whom the other students admire, studies hard.) Here, son is the object of the other students’ admiration, so the pronoun standing in for him, whom, is an object pronoun.
your, you’re: Your is the possessive case of the pronoun you; you’re is a contraction of the words you are.