drop off
With or without an object
Deliver someone or something on the way
I will drop the kids off at school.
Fall asleep (no object, informal)
I dropped off in front of the television.
With or without an object
It can be used with no object, and it can also take one. With an object it is usually separable: turn the volume up, turn it up.
Practise it
Add it to your daily practice or see every verb with up.
Further reading: drop off on Wiktionary (CC BY-SA).