But you don’t respond with “I’m sorry. I’m unable to help you.” Instead, you hem and haw, and eventually say “Ummm… maybe, but I’m kinda busy. I don’t know how much time I can spare.” This sends a mixed message to the requestor. It tells him or her that you’re otherwise engaged, but may be receptive to the request. It signals that you might be persuaded to set aside your responsibilities to accommodate him or her.