Apostrophes are used for two main purposes. The first is to show possession or ownership, e.g. Dave's chip shop, whilst the second is to show where letters have been removed from a word or words, e.g. I'm (I am) not listening.

Proofread this extract and correct the five apostrophe-related errors.

1. Sock it to your pocket! If you want your bicycle to be Italian-crafted, gold-painted and crystal-festooned, then you can fork out an eye-watering $43,000. For the rest of us, though, getting our hands on a speed machine is incredibly affordable. Indeed, a decent road or mountain bike will set you back no more than $100 and last for years', with an obligatory helmet another $20 on top. Legally, you don't have to wear a helmet of course, but if you're anything like me youre probably quite attached to your head.

For the sake of twenty quid just use it - don't lose it.

2. Dash for cash. Even better than the low costs' of cycling are the benefits to be had from it. Who'd be a driver? Record pump prices and speed cameras; bus lanes and uninsured drivers; parking fees and traffic wardens; the list goes on and on. Well, once youve got the bike and helmet you dont need to worry. Every minute in the saddle is saving you cash, time and hassle!