Study the information about phrasal verbs with on/off.
1. We use on/off for lights, machines
The light is on.
Turn the light on/off.
Shall we leave the lights on or turn them off?
2. On and off are used for talking about events.
Go on = happen
Call something off = cancel it
Put something off, put off doing something = delay it
The open concert had to be called off because of the weather.
3. Use on or off, when you talk about clothes.
Put on glasses, clothes, make-up
Put on weight = get heavier
Try on = see if it is good or not
Take off clothes, glasses.
It was warm, so I took off my jacket.
4. Off = away from a person or place.
Be off (to a place)
Be off (to a place)
Walk off, run off, drive off, ride off, go off
Set off = start a journey
Take off = leave the ground (for planes)
See smb. off = go with them to the airport/station to say goodbye
We set off very early to avoid the traffic.
Next week I am off to Paris.