Possible Clues:

• Nonliteral language features
• Individual styles of speaking
• 'I had M x 10, in manners of speaking (6)'
• Vernacular phrases
• Seems I had MMMMMMMMMM, in a manner of speaking
• ''Eat crow'' and ''talk turkey''
• Sayings as of a people or group
• I'd better keep Isle of Man's expressions
• See red, talk a blue streak, etc.
• Manners of speaking from identity of mythical princess on manuscript