There are effectively two ways to use the apostrophe To show Possession. That means, to indicate that something belongs to someone/something. For example, "John's pen" means the pen belonging to John. The very general rule of thumb is that if the word ends in s the apostrophe comes after the s, if it doesn't the apostrophe comes before the s. Examples The child's book, which is a children's book is currently at the parents' house. The musician's flute is currently in Lewis' locker. The exception with regard to names are circumstances where you would naturally pronounce the s, for example "It's Charles's pen" One key exception is where the word itself denotes possession, for example, ours, theirs, his, hers. There are other, less usual exceptions, so if you're not sure, check. To Indicate an Ommission Sometimes it is possible to run two words together or shorten a word by taking out letters. In those cases the missing letter or letters are replaced with an apostrophe. Example "I should have" can be shortened to "I should've" the h and a are taken out and replaced by the apostrophe. Again, in the words "It's" "That's" "What's" etc the apostrophe replaces an i "It is" "That is" "What is" In the words "They'd" We'd" "You've" "They've" the apostrophe replaces h and a "They had" "We had" "They have" "You have" If you're wondering whether a word should have an apostrophe, then check if you can expand it into two words or more. Common Errors It's and its. Ask yourself is the word a contraction of two words (it is) or is it a word that denotes possession (belonging to it)? "It's (It is) unlikely the chicken would have noticed one of its eggs (The eggs belonging to it) was missing." Your and you're "You're(you are) wrong if you say your eyes (the eyes that belong to you) are not pretty." Their and they're "They're (they are) in no hurry to get their arses (the arses belonging to them) out of my way." I hope this has made the apostrophe's role a little clearer. Remember, there will always be exceptions and if anyone has any further pearls of wisdom please feel free to drop them in the comments. I love to learn.
