Accept vs. Except

"Accept" and "Except" sound very similar when spoken but have two entirely different meanings.  The latter is often written in error when the former is meant.

To accept means to receive willingly ("Will you accept money for driving me to the store?") or to respond affirmatively, as with an invitation ("I will accept your offer to drive me to the store.").  Check out this page on Answers.com for a complete list of definitions.

Except means excluding ("Everyone except me is going to the store.").  Several more definitions can be found here on Dictionary.com.

Incorrect: "He will not except money for driving me to the store."
Correct: "He will not accept money for driving me to the store."

Is it Aloud or Allowed?

The word allow means permit, and its past tense is "allowed," not "aloud."  The word aloud means "out loud."

Incorrect: "He is not aloud to go to the store by himself."
Correct: "He is not allowed to go to the store by himself."
Correct: "I said that aloud without meaning to."

Truly Awful: "E" is for Error

To "e" or not to "e"?  No question here.

Two words I often see misspelled are "truly" and "awful."  There is no "e" in either of these words.

True, the root word of "truly" is true, but the "e" is dropped when the -ly is added.

Incorrect: This blog post is truely aweful.
Correct: This blog post is truly awful.

Oh, well, my posts can't all be Shakespearean or poetic!  My goal is to help folks become better writers by avoiding common spelling/grammatical errors, not to have an award-winning blog.  Sometimes the simplest way is the best way.

Two/too/to

The correct spelling for the number 2 is "two."  Think "twice" before spelling it out.  There's a "w" in both words, as well as in other variations of the number such as "twenty" and "twins."

When the meaning is "also" or "excessive," the word is spelled "too."  For any usage other than the foregoing, the proper word is "to."  ("I am going to the store.  They are going to the store, too."  "There are too many people to fit in the car.")  One way to remember the distinction is to think of the way it sounds when spoken.  Technically, the words are pronounced the same, but some people emphasize the "oo" sound of the word "too" more than they do with "to," especially when they're speaking quickly (as we all do sometimes!).  Another way to remember is to keep in mind that the word "too," which signifies "in addition" or "in excess," is the one with the extra "o."

Incorrect: "I am going too the store."
Correct: "I am going to the store."

Incorrect: "This is to much money."
Correct: "This is too much money."

Incorrect: "She will be going to."
Correct: "She will be going too."

Have vs. Of

Quite often, people are thrown by the way a phrase is pronounced, and they subsequently carry the confusion into their written text.  I often see incorrect usage of the word "of," as in the following examples: Should of / Would of / Could of / Must of.  There are no such expressions in American English.  In all cases, the second word should be have, not of.  The correct phrases are should have, would have, could have, and must have.

When these phrases are spoken, people will often use the contracted form of the two words, as in: Should've/Would've/Could've/Must've, which doubtless led to the mistaken belief that the second word is "of" rather than "have."  Sometimes in casual speech, folks will use the slang terms "shoulda," "woulda," "coulda" and even "musta," which helps to blur things further, especially given the fact that the slang word "kinda" does mean "kind of."  In informal writing, the proper and correct contractions for Should have/Would have/Could have/Must have are Should've/Would've/Could've/Must've.  In formal writing, it is best to spell out the two words.  In any case, the word "of" is never used.

The foregoing refers to phrases of intent.  For other usages, such as "I must have a cup of coffee now" or "The dog should have a bath," it would be incorrect to write or say "must've" or "should've."

To summarize:

Should of, would of, could of and must of are all incorrect.
The correct phrases are: Should have, would have, could have, and must have.

The contractions should've, would've, could've, and must've are used informally.

Incorrect: "We should of gone to the beach."  "I must of left my bathing suit at home."
Correct: "We should have gone to the beach.  "I must have left my bathing suit at home."  "We could've gone to the beach today."  "We would've gone to the beach if it hadn't rained."

They're/Their/There

Their, there and they're are soundalike words that have entirely different meanings.  Starting with the easiest one to define, the contraction "they're" means "they are" - and that's all it means.  Using anything other than "they're" for "they are" is incorrect, as is using "they're" to mean anything but "they are."  Further, the usage of "they're" for "they are" presumes that one or more words follow the contraction.  Writing or saying "They're late" is correct, but writing/saying "Here they're" for "Here they are" isn't.

As for the other two, the word "there" has multiple meanings, but possession isn't one of them.  Many people write "there" when they mean to use "their," as in belonging to two or more people ("They need to watch their language."  "They're out of their minds.").  Their is a possessive pronoun, just like your, our, his or her.

For anything other than "they are" (they're) or "belonging to them" (their), the correct word is there.  There often refers to a place or destination, and an easy way to remember this is to keep in mind that the words "where" and "here," which also refer to places/destinations, are spelled similarly, and "where" and "there" both have the word "here" in them.  ("There they are!  They're late, and they've forgotten their books.")

Incorrect: "Their out of there minds."
Correct: "They're out of their minds."

Incorrect: "Their they are."
Correct: "There they are."

Incorrect: "They forgot they're books."
Correct: "They forgot their books."

Your vs. You're

"Your" is a possessive pronoun, meaning belonging to you (see also the entry for yours).  An example of proper usage is: "Is that your bicycle?"  When intending to convey "you are," the word that should be used is "you're."  "You're" is the contraction for "you are."  The words "your" and "you're" are often mixed up in informal writing, mainly by using the former in place of the latter (although I've also seen the error made in reverse).

Incorrect: "Your the best."

Correct: "You're the best."

Correct: "You're taking your bicycle with you, aren't you?"

Summary: If you mean "you are," use "you're."  If not, "your" is the spelling that should be used.