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'?

If you grew up watching Sesame Street, chances are your kids ... He also has a speech impediment that makes pronouncing the letter "R" challenging. Bert is a vibrant, yellow, banana-shaped ...