Watch as Elmo sits in an umpire's chair and debates the two letters found on Federer's On-branded sneakers: Is it 'Q' and 'C' or 'O' and 'N'?

Roger Federer is a marketing powerhouse on his own, and it's best put in Nike's former tennis director Mike Nakajima's words ...

The English We Speak is your chance to catch up on the very latest English words and phrases. In under 3 minutes, we help you stay ahead of the pack by giving you 'must have' phrases that you can ...