Spelling

The easiest way to check for spelling is to use your word processor’s native spell checker. While a spell-checker is a reliable tool, it won’t detect the most common spelling errors: words that sound the same but are spelled differently and have different meanings (homophones) and hyphenated words.

Reviewing the basic rules for these types of errors may help you avoid them in the future.

Homophones

Consider this sentence:

Their planning to except the affect of a stream’s water flow on it’s bed.

None of the words are technically misspelled; they are contextually misspelled. Here is the corrected sentence:

They’re planning to accept the effect of a stream’s water flow on its bed.

Review these and other common homophone misspellings, as well as the corrective rules and relevant examples [1]:

Homophones Rules Examples[1]
their, there, they’re

Use their as a possessive of the pronoun “they.”

Use there to indicate place.

Use they’re as a conjunction meaning “they are.”

Their project will take five days to complete.

Set the wire over there on the table.

They’re coming tomorrow to inspect the mainframe.

accept, except

Use accept to mean “to receive or agree.”

Use except to mean “other than.”

I accept your invitation.

Everyone attended the conference except Jim.

affect, effect

Use affect to mean “to influence.”

Use effect most commonly to mean “result or consequence” or sometimes “to accomplish.”

The small widget affects the large one.

The effect of his research was minimal.

Her work effects a major change in the field.

its, it’s

Use its as a possessive of the pronoun “it.”

Use it’s to mean “it is” or “it has.”

<p?Its monitor burned out yesterday.

It’s too late to meet with our colleagues in Australia.

than, then

Use than in comparison statements, statements of preference, or to suggest quantities beyond a specified amount.

Use then to mean a time other than now and next, or to precede a conclusion.

She is smarter than I am.

I would rather finish my project than sleep.

Start with more than one integer.

He will call you then.

First, I have to break down the structure, then I can rebuild it.

If you prepared, then the work should be easier.

to, too, two

Use to as a preposition or as part of an infinitive verb.

Use too to mean “very” or “also.” 

Use two to mean “the number two.”

He went to the lab first thing to check the experiment.

She was pleased with the results, too.

He broke two widgets.

your, you’re

Use your as a possessive of the pronoun “you.”

Use you’re to mean “you are.”

Your pocket is full.

You’re already writing much better than you used to!

Hyphenated words

Compound words, or two words joined together to form a new word, cause the most common hyphenation errors. The Purdue University Online Writing Lab (OWL) outlines the following hyphenation rules to correct many of those errors [2]:

Hyphenate compound adjectives that occur before a noun, but not after:
e.g., Select a ground-tied speaker. The selected speaker is ground tied.

Hyphenate words that begin with ex-, self-, and all-:
e.g., ex-manager, self-employed, all-purpose

Hyphenate words that end with –elect:
e.g.,President-elect, Committee-elect

Hyphenate words with a prefix and capitalized word, but not words with a modifier and capitalized word:
e.g., mid-September (but not: late September), non-Americans (but not: elderly Americans)

Hyphenate words that would be confusing or awkward without a hyphen:
e.g., re-sign a contract (but not: resign from a position), shell-like (but not: childlike)

Hyphenate words with figures or single letters:
e.g., mid-1990s, T-shirt<, forty-seven.

Use hyphens in “compound modifiers,” [3]:
e.g., a long-standing principle, well-defined rules, a copper-producing region, her new-found knowledge

If you’re unsure about any rule, consult a dictionary or style guide for clarity.

References

[1] Spelling: Common words that sound alike. Purdue Online Writing Lab. [Online]. Available: http://owl.english.purdue.edu/owl/resource/660/01

[2] S. M. Conrey and K. Stolley. Hyphen use. Purdue Online Writing Lab. [Online]. Available: http://owl.english.purdue.edu/owl/resource/576/01/

[3] L. Trask. (1997). The hyphen. University of Sussex. [Online]. Available: http://www.informatics.sussex.ac.uk/department/docs/punctuation/node24.html