Why is my phone not vibrate

To turn vibration on or off:

1. Slide two fingers downwards starting from the top of the screen.
2. Press the sound mode icon the necessary number of times to turn vibration on or off.
3. Press the Home key to return to the home screen.

Or:

Go to Settings > Sounds and Vibration > Vibration Intensity and make sure the switch is turned on. If your phone is in silent mode, it will not vibrate.