Something I've learned (the hard way, as many of my lessons learned,) has been to respond promptly to an inquiry.
Would you like to get together this weekend?
I'm not sure. Let me check my schedule and get back to you.
Acknowledgement. It feels good to be acknowledged. Why is it so important? Because it reduces the feeling of unknown.
Unknown is, in my own estimation, one of the greatest stressors for humans. There is a general fear of the things that we don't know. The fear of the future.
I'm certainly not saying that every person is paralyzed by the fear of the unknown. It causes stress. You call and leave a message regarding school. When will I get a call back? The dentist office calls to ask if you can reschedule. You call back to tell them you're unsure about the timing but will get back to them.
So when someone asks something of you, reply quickly. You don't have to have the answer, but telling the person that their inquiry is being pursued will bring relief to him and make you look like you care.