Possible Clues:

• 'Sorry, can't do it'
• "Sorry, can't do it"
• Casual, dismissive response
• "Actually, I'll pass"
• “Don’t think so”
• "Hmm, I don't think so"
• 'Hmm ... not likely'
• 'You might think so, but ...'
• 'Yeah ... you can just forget about it'
• 'Sorry, that's not happening'