Possible Clues:

• Fats Waller's '___ Misbehavin''
• "Say it __ so!"
• ''Oklahoma!'' contraction
• ''It ___ over 'til it's over''
• Frowned-upon contraction
• "___ it the truth!"
• Isn't for the uneducated?
• 'You -- kiddin'!'
• Beatles "___ She Sweet"
• Ungrammatical contraction