Homophones - words that sound alike but are spelled differently - can be particularly pesky.
Regardless, you should never choose incorrectly in these nine situations:
1. 'Your' vs. 'You're'
"Your" is a possessive pronoun, while "you're" is a contraction of "you are."
Example 1: You're pretty.
Example 2: Give me some of your whiskey.
2. 'It's' vs. 'Its'
Normally, an apostrophe symbolizes possession, as in, "I took the dog's bone." But because apostrophes also replace omitted letters - as in "don't" - the "it's" vs. "its" decision gets complicated.
Use "its" as the possessive pronoun and "it's" for the shortened version of "it is."
Example 1: The dog chewed on its bone.
Example 2: It's raining.
3. 'Then' vs. 'Than'
"Then" conveys time, while "than" is used for comparison.
Example 1: We left the party and then went home.
Example 2: We would rather go home than stay at the party.
4. 'There' vs. 'They're' vs. 'Their'
"There" is a location. "Their" is a possessive pronoun. And "they're" is a contraction of "they are."
Use them wisely.
5. 'We're' vs. 'Were'
"We're" is a contraction of "we are" and "were" is the past tense of "are."
6. 'Affect' vs. 'Effect'
"Affect" is a verb and "effect" is a noun.
There are, however, rare exceptions. For example, someone can "effect change" and "affect" can be a psychological symptom.
Example: How did that affect you?
Example: What effect did that have on you?
7. 'Two' vs. 'Too' vs. 'To'
"Two" is a number.
"To" is a preposition. It's used to express motion, although often not literally, toward a person, place, or thing.
And "too" is a synonym for "also."
8. 'Into' vs. 'In To'
"Into" is a preposition that indicates movement or transformation, while "in to," as two separate words, does not.
Example: We drove the car into the lake.
Example: I turned my test in to the teacher.
In the latter example, if you wrote "into," you're implying you literally changed your test into your teacher.
9. 'Alot'
"Alot" isn't a word. This phrase is always two separate words: a lot.
10. 'Who' vs. 'Whom'
Use who to refer to the subject of a sentence and whom to refer to the object of the verb or preposition. Shortcut: Remember that who does it to whom.
Example: Who ate my sandwich?
Example: Whom should I ask?
11. 'Whose' vs. 'Who's'
Use "whose" to assign ownership to someone and "who's" as the contraction of "who is."
Example: Whose backpack is on that table?
Example: Who's going to the movies tonight?