Homonym abuse is the problem. Homonyms -- words that sound alike but are spelled differently and mean different things -- have taken a terrible beating lately. It is of course easy to mis-type in the heat of the moment, but serious and persistent errors must be addressed. The excellent thing about homonyms, however, is that if you simply take a moment to memorize which is which you will rarely be confused thereafter.
Their / They're / There:
- Their is a possessive word, as in "That is their idea".
- They're means "they are", which may handily be seen as a contraction because of our friend the apostrophe's signal. The apostrophe is replacing the letter "a" in "are".
- There is a direction, as in "over there".
Its / It's:
Again, our friend the apostrophe can help us out, as it signals a contraction:
- "It's" means "it is", and the apostrophe is again taking the place of an initial vowel. If you mean to describe something, use "it's".
- If you are referring to a possession -- "The cup sat on its saucer" (that is to say, on the saucer belonging to the cup) -- omit the apostrophe. This will seem counter-intuitive at first, since we say things like "Christine's chocolate" or "Canada's national sport" and use an apostrophe in this case. But IT is different, and if you take care, you will soon get used to it.
Your / You're:
This one drives me particularly crazy because, as with the examples above, it's really quite simple to learn and then to memorize. Grammar, mostly, is not difficult -- it's merely tedious, but that's enough to put people off it. I am digressing, however. Here's the distinction:
- The word "your" is possessive. "Your boots" are the boots that you own. "Your crazy" is the crazy that you own.
- "You're" has an apostrophe in it, once again signalling a contraction. It means "you are", and so you can say "you're special" or "you're happy".
- Mixing these two up can be disastrous. Consider the difference between "your nuts" and "you're nuts", by way of brief example.
- Sight/Site: The first is one of your five senses. The latter is more of a place, like a camp site or a web site.
- Coarse/Course: Coarse means rough. Course might mean something like path. It is also used in the phrase "of course".
- To/Too/Two: The first is probably the most commonly used, forming part of the oft-used "to do" -- if you are going to the store, or off to do the dishes, or intending to give me lots of money, use this word. The middle version means "as well" or "also". The last is the number that we all know and love.
- Effect/Affect: The former is the result of the latter. You affect something in order to have an effect on it.
- Bored/Board: Bored is what you are when there's nothing to do. A board either comes from a tree, has -game attached to the end of it, or holds periodic management meetings.
Did I miss any obvious ones? Out them in the comments!
(Note: Anyone who comments about how grammar is obsolete -- and that as long as you can be understood, even with errors, everything's good enough -- will be summarily executed. Yes, I can understand you, with effort, if you say things like "Your going too have a bad affect", but I won't assume you're clever. I spent four hours copy-editing yesterday; don't cross me.)