Phrasal Verbs consist of a verb plus a particle:
verb + adverb or verb + preposition or verb + adverb + preposition.
The meaning of this combination is mostly very different from the verb and the adverb or preposition alone.
There are no rules that might explain how phrasal verbs are formed correctly - all you can do is look them up in a dictionary and study their meanings.
In fact many phrasal verbs are metaphorical, and if you understand the metaphors they use, it will be easier to understand and remember their meanings.
Phrasal verbs are mainly used in spoken English and informal texts.
Many phrasal verbs are transitive, meaning that they take an object. Other phrasal verbs can stand alone (intransitive verbs).
Some phrasal verbs are separable (the verb and the preposition can be separated, putting the object in the middle), while others are inseparable (the object must come at the end because the verb and the preposition must stay together).
Separable verb:
Correct: Put on your coat.
Correct: Put your coat on.
Inseparable verb:
Correct: Get on a bus.
Incorrect: Get a bus on.

The Preposition OFF is the opposite of ON. It is used for two basic meanings: firstly, if an object is moving in a direction away from the speaker or another object; and secondly, if an object is in a state of non-operation or in a state of non-existence.

Phrasal verbs with OFF, their meanings and examples


LEAVING a place, the ground, a surface, or going away from something
Back off – Retreat. Everyone back off and let the doctor through.
Be off - Depart, leave. I should be off now if I am going to catch the next bus.
Buzz off - Leave somewhere. I've got to buzz off.
Clear off - Leave somewhere quickly. I wished the door to door salesman would clear off so that I could get back to watching the football on television.
Dash off - Leave somewhere quickly. Do something quickly. When the bell rang he dashed off to class.
Drive off - Drive away from a place. She got in her car and drove off.
Drop off - Take something or someone to a place and leave it or them there/Fall asleep. I dropped off the kids at the party.
Dry off - Dry something quickly, or dry the surface. I dried myself off with a towel and got dressed.
Fall off - To drop or descend from the top of something. I fell off the ladder and bruised my knee.
Get off - Finish, leave work/leave a bus, train, plane etc. (anything apart from cars). What time did they get off work?

Give off - Emit pollution or something else unpleasant. This chemical reaction gives off a lot of energy.
Go off - Leave a place. They went off without saying goodbye.
Head off - Leave somewhere to go to another place. She's heading off to New York City next week.
Make off - Leave somewhere in a hurry. He certainly made off in a hurry!
Peel off - Leave a group by moving in a different direction. One motorbike peeled off from the formation and circled round behind the rest.
Pop off - Go out for a short time. Bye, I must pop off.
Ride off - Go away on a bike, horse, etc. She got on her motorbike and rode off.
Run off - To flee, to run away with someone. Their dad ran off when they were little.
Rush off - Depart in a hurry. They rushed off to the catch the next bus. 
Set off - Start a journey/Cause, trigger events. What time are you setting off tomorrow morning?
Shoot off - Leave promptly and quickly. I'll have to shoot off as soon as the lecture finishes.
Take off - When a plane departs or leaves the ground. The plane should take off on time.
Tear off - Leave at high speed. He got in his car and tore off down the road.

CANCEL or DELAY 
Blow off - Not keep an appointment/ Ignore. Just blow off his comments, he's only joking.
Call off – Cancel/ Order someone to stop attacking. The game was called off because of bad weather.
Cry off - To cancel an arrangement. She usually says she'll be there and then cries off at the last minute.
Hold off (on someone or something) - to delay doing something. Let's hold off making a decision until next week.
Rain off - Be postponed or stopped by rain (usually passive). His hockey match was rained off.
Put off - Postpone/Stop liking something or somebody. I’ll put off doing the washing until tomorrow.
Stave off - Delay, prevent something from happening. We were hoping to stave off these difficult decisions until September.


REMOVE, REDUCE, DECREASE
Burn off - Remove by burning or similar process. They managed to burn off the excess wax.
Chew off - Remove by biting. The puppy chewed off my shoe laces.
Clean off - Remove dirt or something dirty. After dinner I cleaned off the table.
Ease off - Reduce pressure. If she doesn’t ease off at work, she’ll make herself ill.
Fall off – Decrease. Sales always fall off in the winter months.
Flog off - Sell something cheaply to get rid of it. The council may be planning to flog off most of the land to developers.
Knock off - Reduce the price of something/Produce or create something quickly. They’ll knock something off the price if you collect it yourself.
Shave off - Shave completely/Reduce by a small amount. The new high speed trains will shave 1 hour off the journey time.
Slip off - Remove clothes or shoes. Slip off your shirt so that I can sew the button back on.
Slack off - Reduce one's effort, perform with less enthusiasm and energy. Tom slacked off at work and started surfing the Internet.
Take off - Reduce the price of an item/ Remove clothes or shoes. I’d better take my shoes off before stepping on the new carpet.
Tear off - Remove part of a form or letter using your hands, not scissors. Just tear off the return slip at the bottom of the form and sign it.
Throw off - Remove item of clothing quickly/Get rid of. John threw off his coat and dived into the water.

NOT OPERATING or BEING USED (about a machine or piece of electrical equipment)
Come off - When something breaks off. I picked the bag up and the handle came off in my hand.
Go off - Stop working (electric/electronic equipment). The heating goes off at ten o’clock.
Power off - Cut the electricity to a computer or device to turn it off. You mustn't power it off while it is updating.
Turn off - Stop a machine. How do you turn the computer off?
Set off - Explode a bomb/ Ring an alarm. Kate pushed open the front door, which set off the alarm.
Shut off – Stop something from operating or fluid flowing in a pipe. Shut off the tap when you have finished watering the garden.


NOT AT WORK OR SCHOOL
Bunk off - Not be at school or work when you should. A lot of people bunk off early on Friday.
Goof off - Avoid or leave work. They've goofed off and gone to the pub.
Sag off - Not go to school or work, or leave early when you shouldn't. I was bored so I sagged off work early and went home.
Skive off - Avoid doing work or other duty. He was always skiving off and going to the cinema.

FOOD that is OFF IS NO LONGER FRESH and is not good to eat
Be off - Be bad. This yoghurt must be off.
Go off - Go bad. That milk has gone off.


NO LONGER EATING, USING, DOING, EXISTING

Go off - No longer doing. My son has gone off playing rugby.
Die off - Become extinct. The generation that fought in the war are all dying off.
Cast off - Dispose, get rid of. It took many years for him to cast off his bad reputation.

NO LONGER CONNECTED to someone or something
Break off - Break a piece from something/End a relationship. I’ve decided to break it off with her.
Check off - Mark something on a list as done. Please check each name off on the list.
Cross off - Delete, remove from a list. Did you cross her name off the guest list?
Cut off - Disconnect/Isolate or make inaccessible. If we don’t pay the bill, the electricity will be cut off.
Mark off - Tick, cross out. He marked off the names of all the suitable candidates.
Measure off - Measure something and mark the point where it ends or will be cut. He took the fabric and measured off a couple of metres.
Tick off - Put a mark on an item in a list when it has been dealt with. I ticked off the children’s names as they arrived.

IN A GOOD or BAD SITUATION
Bring off - Succeed with something difficult. If they can bring off the deal, they’ll be able to retire.
Carry off - Win, succeed. I thought he carried off the part of the play with great skill.
Come off - Be successful. The party didn’t quite come off as we had hoped.
Fend off - Resist something successfully/Push an attacker away. So far he has managed to fend off attacks on his reputation.
Pull off - Manage to do something difficult or tricky/Start moving (vehicles). The team pulled off a surprise victory in the semi-final.

SEND
Bundle off - Send someone somewhere. She was bundled off to boarding school when she was seven years old.
Fire off - Send quickly, angrily or many (letter, emails, etc)/Shoot, fire a gun (usually repeatedly). I sat down and fired off a letter to my MP.
Pack off - Send someone away. I packed her off to my sister's.
Send off - Post a letter. Have you sent off your application form yet?

FINISH
Cap off - Finish or complete, often with some decisive action. He capped off the meeting with a radical proposal.
Choke off - Stop or restrict. If prices are too high, demand is choked off.
Finish off - Finish completely. I will finish off the essay tonight.
Knock off - Finish work for the day. Do you want to knock off early tonight?
Lay off - To terminate someone's employment, make an employee redundant. They’ve had to cut back production and lay off workers.
Polish off - Finish, consume. He polished off the whole pie.
Ring off - Finish a phone conversation. He rang off before she had a chance to reply.
Round off - Finish something in a satisfactory manner. We rounded off the meal with a cheesecake.
Sign off - End a message/Stop doing something to leave. He signed off - ‘Yours sincerely, John Smith’.
Shake off - Get rid of an illness. We shook off our fears.
Stop off - Break a journey. We stopped off in town on the way to Kate's house.
Top off - Finish something in a special way/Fill something completely that is not empty. We topped off the evening with a carriage ride.
Write off - Cancel from an account as a loss/ to drop someone or something from consideration. The £500 they have spent will have to be written off.

SEPARATE
Cream off - Separate the best or most talented people so that they can receive special or different treatment. They had a plan to cream off the brightest children.
Hive off - Separate part of a company or service, often by selling it. The plan is to hive off individual companies as soon as they are profitable.
Rip off - To steal from, to exploit, cheat, or defraud. Cars get ripped off all the time round here.
See off - Go to the airport, station, etc., to say goodbye to someone. Kate saw Mary off at the airport.
Wave off - Go to a place where someone is leaving to wave goodbye. She stood at the gate and waved her children off to school.

CONFRONT
Face off – Confront. Soldiers and protesters faced off during the riots.
Fight off - Fight an attacker and force them back/Resist an illness or emotion. The old lady managed to fight off her attackers.
Fob off - Make or persuade someone to accept something/Lie or deceive someone. Customers complain they’re being fobbed off. 
Frighten off - Scare someone so much that they go away or stop doing something they had planned. Be quiet or you'll frighten off the butterfly.
Front off - Confront someone and let them know you are prepared to fight. The two guys fronted each other off.
Go off - Start to dislike. I went off the idea of buying a sports car after I found out how much it would cost.
Hack off - Annoy. He leaves all the difficult stuff for me to do, and it really hacks me off.
Head off - Stop someone or force them to change direction. Let’s try and head them off before they cross the bridge.
Piss off - To annoy, irritate, or disappoint. It really pisses me off when you talk like that.
Scare off - Make someone sufficiently frightened that he or she goes away. The country’s high murder rate has scared off the tourists.
Shrug off - Disregard something, not consider it important or harmful. They’ve clearly shrugged off the disappointment of last week’s defeat.
Slag off - Criticise heavily. You shouldn’t slag him off without knowing the facts.
Sound off - To express your opinions forcefully. He's always sounding off about how he thinks the country should be run.
Square off - Confront someone or prepare to fight them. The two retail giants are squaring off this month with advertising campaigns.
Tell off - To rebuke severely. Mia got told off for talking in class.
Tick off - Annoy/Scold. He ticked me off for parking in front of his house.

START
Bounce off - Test ideas. I have been thinking about it, so let me bounce a few ideas off you.
Hit it off - Have a good relationship from the first time you meet a person. I didn’t really hit it off with his sister.
Kick off - Begin something, especially a football match. The game kicks off at 9.30.
Start off - Make something start/Begin life, a career or existence/Begin a journey. We don’t want to start off a riot.
Trigger off - Start, set off. The report has triggered a fierce response from the CEO.


SEPARATED from a particular area
Block off - Obstruct an entrance or exit to prevent people from using it. The road was blocked off whilst they mended the gas leak.
Fence off - Enclose an area to keep animals or people either in or out. They fenced off the bottom end of the garden.
Rope off - Extend ropes or barriers across or around an area. The police roped off the crime scene.
Screen off - Separate a part of a room with something like a curtain, screen, etc. We could screen off this part of the room.
Shut off/Close off - Close, prevent access. They have shut off access to the rear car park.


There are a lot of SWEAR WORDS with rude and offensive meaning “GO AWAY”, ”GET LOST”:
Naff off
Pig off
Piss off. Why don't you just piss off - you've caused enough problems already!
Push off
Rack off


OTHERS
Doze off - To fall into a light sleep. I dozed off in front of the television.
Laugh off - Pretend something (an injury, news, etc.) isn’t important. He laughed off the incident.
Let off - Not punish. The police arrested the leader and let off the rest of the gang with only a warning.
Live off - Use money earned/Be financially supported. All his life he had lived off his father.
Marry off - Find a husband or wife for someone, especially your children. She was married off to the local doctor by the age of 16.
Nod off - Fall asleep. I nodded off after lunch.
Show off - Behave in a way so as to attract attention/Display something you are proud of. Stop showing off!