I was given the nickname 'Apostrophe Dave', as I spotted a couple of things other people didn't, including a couple that others missed, including the trainer.
He pointed me at this BBC test: http://www.bbc.co.uk/skillswise/words/grammar/punctuation/apostrophes/game.shtml
(second one on that page), and said that the level 3 test was hard.
Naturally I tried it when I got back to my desk, and scored full marks.
Right, your turn. How did you do?