shut off
Separable
Stop a supply or a machine from working
They shut off the water while the pipes were repaired.
Separable
The object can go between the verb and the particle: turn the light off, or turn off the light. When the object is a pronoun it must go in the middle: turn it off, never turn off it.
The particle: off
This verb belongs to the group ‘switching and shutting off’.
Others in the group: switch off, turn off.
Practise it
Add it to your daily practice or see every verb with off.
Further reading: shut off on Wiktionary (CC BY-SA).