Editors cringe every time they see words like loose and lose, or its and it's used improperly. Sometimes it's a simple typo and other times the writer has misunderstood usage or definition. Writers have to remember many rules about punctuation, grammar and format and occasionally, simple rules like usage slip our minds.
There are hundreds of words that sound the same but have different meanings. You could probably fill a book if you listed all of them. In fact, someone probably already has.
But let's take a look at the ones that I find are used and mistaken most often:
Accept or Except
Accept is a verb meaning to receive or to be received. It is also used to imply something is considered right or proper. You would accept the role of Captain offered to you after the cheerleading squad accepts you as a member. Except is a preposition meaning other than or the exclusion of. "Everyone except Jane received promotions."
Blond or Blonde
This one is tough because the rule is a bit confusing. Proper usage as a noun requires that you use blond when using the masculine form, "The blond jumped in front of the car, using his body to shield the little girl." and you'd use blonde when its the feminine form, "The blonde flipped her hair, confident that all eyes were now on her." However, when using this word as an adjective, you'd drop the 'e' whether referring to a male or a female. "Her blond hair hung about her face in limp strings."
Cite, Sight, or Site
Cite means to quote or document a statement or events. Site means a position, place, or location. You would go to the job site with your head hung low, knowing your buddies would cite the events of last night for you in great detail. Sight means vision, and is used when speaking of seeing things with your eyes. "She was a sight to behold with the dozen tentacles waving and a third eye staring back at him."
Dam or Damn
Damn is a curse word. A dam is a structure that holds back water.
Desert or Dessert
Dessert is that tasty sweet food you eat after a meal. "She made pie for dessert." Desert is a dry, arid piece of land or it might mean to leave or abandon something or someone. "He snuck off into the desert, knowing he'd be labelled a traitor for deserting his comrades."
Hear or Here
Hear is to listen. Here means in this location, this place. "I can't hear you." She yelled. "Why are there so many people here?"
Its or It's
These are probably the most commonly confused words in fiction writing. Even experienced writers occasionally forget the difference between the two. Its shows possession. "The dog hid its bone." It's is the contraction for it is. "It's time to go to school." The confusion is likely because in most cases when you're showing possession, you'd include the apostrophe.
Lose or Loose
Okay, often this is a spelling error, a simple typo but it happens so often it warrants a mention. Lose is to misplace something. Loose means to release, unfasten, or to let go of. "He didn't want to lose sight of her, she might get loose." Or, "I'll have to lose ten pounds or loosen my belt a couple of notches."
Sea or See
Sea typically refers to a large body of salt water and is often used when referring to an ocean. See means to look at visually or to perceive with your eye. "The fog grew so thick that he could barely see his hand in front of him, but he could hear the waves crashing to the shore from the sea."
Than or Then
Than and then can be confusing. Which to use and when? Than compares. "She is bigger than her sister, but smaller than all of her brothers." Then means next or at that time. “Julie lifted her drink as if to propose a toast, then dumped the expensive red wine over his head."
Their, There, or They’re
These three are troublesome. Their implies possession; the possessive form of they. There is used when referring to a location. They're is the contraction of they are. "They're going to regret their decision to move there."
Through, Threw, Thorough, or Thru
Wow, that's a lot of confusion. These four words, all sounding the same, can boggle one's mind. Through and thorough are often typos, simple mindless mistakes. Through is used when describing going into or out of something, by means of, or to finish. You walk through a door because you're through with his antics. Thorough is used to mean careful or complete. The police are usually thorough in their investigation of a crime scene. Threw is the past tense of throw. "The boy threw the ball through the window." And you may as well forget thru right now. Toss it from your brain and never think of it again. It's slang for through, and in fiction writing, you shouldn't use it.
Weather or Whether
We all know what weather is, don't we? The rain, sunshine, a blizzard, cold or hot. It's used to describe atmospheric conditions. Whether is a conjunction used when describing alternate possibilities. "He wasn't sure what the weather would be like, but he didn't care whether or not it rained, he wasn't wearing that ugly coat."
Who's or Whose
Whose is the possessive form of who. Who's is the conjunction of who is and should only be used in place of that. These two are enough to drive a writer crazy. Let's end the confusion right now. A good way to know which to use and when is to insert who is into the sentence. Does it make sense? Then you have your answer. "Whose keys are these?" Insert who is to see if you've used the right one. "Who is keys are these?" Makes no sense does it? Great, then whose was the right word to use.
Your or You're
You're is the contraction for you are and your is the possessive form of you. Like who's and whose, you can insert you are into the sentence to know if you've used the right form.
The list of words that writers find confusing is much longer than this, and each writer has their own little issues with certain words and combinations. Knowing their definitions and usage is a simple way to remember how to use them.