One of the more frequent mistakes I see in email and online is confusion between role and roll. These are homophones. They usually make the same sounds in English but they are different words with distinct meanings. One plays a role on a team. One eats a roll for breakfast. One might have a role in a film that requires one to roll down a hill but in any event roll and role are two different words with two distinct uses and meanings.
I also hear and read “chomping at the bit” and “champing at the bit.” They may both be correct but in a formal setting it might be wiser to use “champing at the bit.” Champ is the British and older American usage and chomp seems to be the contemporary American colloquial usage.