In a previous article I wrote for this site, I mentioned that some manual typewriters did not have a key that would produce an exclamation mark and to create one you had to type an apostrophe, then back space and a full stop. All of this came to an end, of course, with the development of the word-processor, when the exclamation mark was given its own key and the full stop and the apostrophe were free to go about their own jobs in the correct manner. Alas, as far as the latter is concerned, incorrect usage can be seen all around, yet if you want your work to look correct, then there are a couple of very simple rules that will help you avoid misplacing your apostrophes.

One of the most common misuses is the so-called greengrocers' apostrophe, which takes its name from the often seen error chalked on blackboards and daubed on windows of those shops to advertise pea's, apple's and banana's etc. Not that there is anything wrong in this - greengrocers are there to sell fruit and vegetables, not to give demonstrations in correct punctuation and I would hazard that proprietors of other shops misplace their apostrophes just as much. Anyway, this apostrophe should only be used to denote possession, for example the boy's kite, the dog's collar and the children's swing. All of which is, as a certain furry animal with a foreign accent might tell us, simples.

Life, however, is never simple and just to keep us on our toes the word 'it' does not have an apostrophe when used to denote possession. We say the snake shed its skin, and the dog wagged its tail and they did it all without the aid of an apostrophe.

For the most common misuse of the apostrophe is when saying 'it's' when the word 'its' should be used. The simple rule to remember here is that the apostrophe in the word 'it's' is there to denote one or more missing letters; it is a contraction of the phrase 'it is', or 'it has'. Therefore, the only time you should use the apostrophe here is when you are making a contraction of one of these phrases. For example, it's raining, it's been a while, and it's a long way to Tipperary. For everything else use 'its.'

Another use of the apostrophe that causes confusion is when it appears immediately after a period of time. For example, both of these are correct:

Six weeks' wages
Six weeks ago

and:

Three months later
Three months' imprisonment

So why does the apostrophe appear after some but not others? Well, the good news is that we needn't even answer that because all we need to know is when to use it and when not to, and there is a simple test that will tell you the correct form with 100% accuracy.

All you have to do is take the number of weeks, days or whatever down to one:

One week's wages
One week ago

As you can see there is a difference in that the former has the letter 's' on the end while the latter does not. Where the 's' is present, the apostrophe follows, (Three weeks' wages), and where there is no 's', there is no apostrophe (Three weeks ago). It's as simple of that.

Getting to know the tricks and tips of Microsoft Word is a bit like getting to know the workings of a car, but taking the time to learn how to use the language correctly is like becoming a better driver.