If you want to improve your writing, make sure you have the following right.
1. “Lets” and “let’s”
Lets is the third-person present form of the verb, let.
My mom lets me make my own decisions, as long as I keep her informed.
Let’s is a contraction of the words let and us.
Let’s go out to eat tonight.
2. “Awhile” and “a while”
According to Oxford, the single word awhile is an adverb meaning “for a short time,” and shouldn’t be confused with the noun use of a while, which means “a period of time.”
We can stand here awhile, but we stood there for a while.
3. “Affect” and “effect”
Affect is used primarily as a verb meaning “to influence or make a difference to.”
The environment was beginning to affect my health.
The effect, on the other hand, is used both as a noun and a verb. It means “a result” as a noun, or “to bring about” as a verb.
She knew the effect her voice had on others. (noun)
The new manager hoped to effect change in her department. (verb)
4. “Each other’s” and “each other”
Each other’s is the possessive form of each other.
We checked each other’s work.
Each others and each others’ are both incorrect.
5. “Years’ experience” and “years experience.”
Years’ experience is a possessive form meaning years of experience.
This position requires a minimum of five years’ experience.
Years experience is incorrect.
6. “A” and “an”
Most English speakers know this one, but it’s still a common writing mistake:
You use a as the article before a noun that begins with a consonant (or consonant sound).
My dad bought a new car yesterday.
In contrast, an comes before a noun that begins with a vowel (or vowel sound).
Would you like an apple?
7. “Everyday” and “every day”
Every day is an adjective meaning “encountered or used routinely, typically, or daily; commonplace.”
He grew tired of everyday chores, like cleaning his room and taking out the garbage.
In contrast, according to Grammarist, “in the two-word phrase every day, the adjective every modifies the noun day,” and the phrase usually functions as an adverb.
The new intern is excited to go to work every day.
8. “You” and “your”
You probably wouldn’t make this mistake when speaking, but it’s common when writing.
For clarity, you is the second-person pronoun and is used to refer to the person (or people) that the speaker is addressing.
I love you.
Your is the possessive form of you.
What’s your name?
Of course, also be careful not to mistakenly use you’re, which is the contraction of the words you and are.
You’re going to the party tonight, aren’t you?
9. “Advice” and “advise”
Advice is a noun meaning a suggestion, a recommendation, or guidance.
Do you have any advice for me?
Advise is a verb meaning to offer a suggestion or recommendation.
I advised you not to go that route.
10. “Its” and “it’s”
It’s is the possessive form of the pronoun it, meaning “belonging to or associated with a thing previously mentioned or easily identified.”
The sour cream is past its expiration date.
It’s is a contraction of the words it is, or it has.
It’s a beautiful day today.