My iPhone 11 keeps vibrating and waking me up at night. I have turned the phone on silent using the hardware button and have turned the volume all of the way down. Can you help me stop my phone from vibrating?
Sure! To stop your iPhone 11 from vibrating, you can enable the Do Not Disturb mode.

Go to Settings > Do Not Disturb > Schedule and set a time for Do Not Disturb to turn on and off automatically every day. In this mode, your phone will not light up or make any sounds or vibrations, even if you receive a call or message.
Will my alarm go off in do not disturb?
Yes, your alarm will still go off even if your iPhone is in Do Not Disturb mode. The purpose of Do Not Disturb mode is to silence incoming calls, messages, and other notifications, but it does not affect the alarm clock. You can set an alarm as usual and it will still sound even if your phone is in Do Not Disturb mode.

It's also worth noting that you can customize the behavior of Do Not Disturb mode to allow certain contacts to reach you even when your phone is in this mode. This can be useful if you want to make sure you receive important calls or messages during the night, while still silencing other notifications. To set up these exceptions, go to Settings > Do Not Disturb.