I used this song just for fun as an end of class relax. I did this worksheet on request of my students who love this song and by the end were singing along to it even if they didn't really understand the true meaning of the lyrics. The fact that they sing and practise the pronunciation is great in itself - they don't even realise how good they pronounce the words! Anyway, this worksheet has many different activities - choosing the right word, gap fill etc. I hope that it comes in useful in your class too!