Possible Clues:

• Common contraction
• "___ be here in a minute" (contraction)
• "___ never know!"
• Classic comic strip “___ Do It Every Time”
• '___ have to pry the buzzer out of my cold, dead hands'--Ken Jennings
• "__ never know what hit 'em!"
• '___ never know'
• '-- never believe it!'
• "__ Do It Every Time," longtime comic strip
• Contraction involving a group