Accept/except
Accept is a verb meaning to receive. Except is usually a preposition that denotes exclusion.
Affect/effect
Affect is a verb that means to influence, and effect is either a noun meaning result or it is a verb meaning to bring about.
Conscience/conscious
Conscience is a noun meaning moral principles. Conscious is an adjective meaning aware.
Definitely/defiantly
Definitely denotes certainty. Defiantly is an adjective describing defiant action or behavior.
Farther/further
Farther usually describes distance, and further suggests a quantity or degree.
Fewer/less
Fewer refers to items that can be counted. Less refers to items that cannot be counted.
Its/it’s
Its refers to the possessive form of the word “it.. It’s is the contraction of “it is.”
Lie/lay
Lie is an intransitive verb meaning to recline or rest on a surface. Its forms are: lie\lay\lain. Lay is a transitive verb meaning to put or place.
Loose, lose
Loose is an adjective meaning not secure. Lose is a verb meaning the opposite of win. Lose also means to misplace.
Than/then
Than is used to note comparisons. Then is to denote time or in if/then statements (If x, then y.)
There/their/they’re
There specifies a place or is a mild expletive. Their is a possessive pronoun. They’re is the contraction of ‘they are.”
To/too/two
To is a preposition. Too is an adverb, and two is a number.
Who/whom
Who is used for subjects and subject complements. Whom is used when dealing with objects. Who spilled the milk? For whom the bell tolls.
Who’s/whose
Who’s is a contraction of “who is.” Whose is a possessive pronoun.
Your/you’re
Your is possessive. You’re is a contraction of “you are.”