Yahoo writes: "While we can rely on a spell checker to catch glaring errors, a computer can’t pick up on all careless mistakes, especially if the word could be correct in a different context. Often word misuse is our mistake. The English language is full of homonyms, or words that have different meanings but sound and look similar, which makes it easy to confuse proper usage. For instance, verbally, you might not even notice the difference between “your” and “you’re.” But in print, the error can lead the reader to perceive you as less intelligent than you are. For this reason, it's important to spell check and proofread your documents, especially for the following common misuses, which are so easy to make, you might even have to check your document a couple times to catch them."