It is so important for writers to carefully consider every word they put on the page and ensure it's the correct word. You will quickly turn off a reader by publishing the phrase "[he] peaks my interest" and your credibility will tank. In order to show that you are a great writer, take great care with the details.
Despite my broad vocabulary, I frequently use a dictionary to make sure the word used in the content is the correct word. I'm not ashamed to make this statement. I use my resources to make the correct decision.
Whether you have an old, dog-eared paperback copy or utilize one of many on-line dictionaries available, don't hesitate to use it. There are also dozens of on-line grammar resources for using tricky words properly.
Below are a few examples of words that are often - quite innocently - misused, but are frustrating nonetheless.
peak vs. pique:
peak = the pointed top of anything. Ex. "the peak of the mountain"
pique = to arouse an emotion or provoke to action, Ex. "that comment piques my interest"
mute vs. moot:
mute = not emitting or having sound of any kind. Ex. "He was born mute."
moot = of little or no practical value or meaning; purely academic. Ex. "that is a moot point"
hanger vs. hangar:
hanger =a contrivance on which things are hung, as a hook. Ex. "she hung the dress on a plastic hanger"
hangar = any relatively wide structure used for housing airplanes or airships. Ex. "his airplane was sheltered in the hangar"
capital vs. capitol:
capital = the city or town that is the official seat of government in a country, state, etc. Ex: "Topeka is the capital of Kansas"
capitol = a building occupied by a state legislature. Ex. "the representatives met at the capitol"
passed vs. past:
passed = past tense of pass. Ex. "the speeding car passed me on the highway"
past = gone by or elapsed in time. Ex. "during the past year"
OR so as to pass by or beyond. Ex. "the troops marched past"
OR beyond in time; later than; after. Ex. "past noon; half past six"
pore vs. pour:
pore = to read carefully. Ex. "she pored over the proposal document"
pour = to cause a flow. Ex. "he poured the milk into a glass"
bated vs. baited:
bated = adjective. Ex. "she waited with bated breath"
baited = verb. Ex. "she baited him with her eyes"
Resource: 200 homonyms, homophones and homographs.