If you're planning to spend an hour in the garden this weekend taking part in the RSPB's Big Garden Birdwatch then also make sure you keep your ears open as well as your eyes. It can sometimes be difficult to spot birds that may be hiding in trees or hedges, but quite often you can hear them before you see them.
Do you know the difference though between what a robin and a blackbird sounds like? If the answer's no then why not take a look at this fantastic guide from the Guardian's website. It gives example of the songs of the birds that you are most likely to spot in your garden.
By the end of the weekend you could be an expert!