Apostrophies are an example of where one can show true mastery so I'll start there (also Annie has been pointing these out to me for months - thanks my nitpicking love). An apostrophe is used to shorten word combinations in the way I just did in the previous sentence. This application is easy to understand and with a proper spell-checker one will generally do fine (if you insist on writing with a quill on a dead tree I cannot help you).
More difficult to intuitively grasp is the usage of apostrophies when they are employed to point to ownership relations such as The Queen's English*. The English is 'of the' Queen and thus an apostrophe is inserted between the Queen and the s. However ...
While The Queen's English thus clearly refers to HMQ (and there can be only one) the queens' English could very well refer to English spoken by an entirely different demographic...
Experts and spelling-nazis wiser than me have been on this for ages so I'll just point to some of the resources I just found and never fathomed existed. Foremost is the Apostrophe Protection Society which is fighting diligently for the continued use and respect for their favourite abused punctuation mark. After having spent more time than I should on researching this issue I tend to agree with Seth Godin that the apostrophe is probably designed to make people look stupid. It's working is all I can say ...
For those who really want to get some practice in applying proper punctuation (and thus prevent the need for re-ordering all the female bathroom-signs in your newly designed hotel) you can have a go at the BBC site (or Beeb as the natives refer to it).
*while it is questionable whether the Queen actually owns the English language the British like to uphold this fantasy to feel they still matter in global affairs - we Dutch know full well we have no impact whatsoever and are resigned to it. This allows us to save a lot on not-having a Navy sized to defend an empire without sunsets.
