pass away means die (e.g. His uncle passed away last night after a long illness.)
pass out means faint or to become unconscious for a short time (e.g. I was hit on the head and passed out.) I was hit on the head and passed out.
pass something out means give the same thing to people (e.g. I'll pass out copies of the report. The professor passed the textbooks out before class.)
pass something up means decline (e.g. I have to pass the invitation up as I already had an appointment at that time. I passed up the job because I am afraid of change.)

pay back money, pay somebody back means return owed money (e.g. If you borrow money, you have to pay it back)
pay for something means be punished for doing something bad (e.g. I paid ten pounds for the meal. That bully will pay for being mean to my little brother.)
Pay off means completely repay a debt (e.g. The mortgage will be paid off in twenty years.)

phone (or call or ring) somebody back means return a phone call (e.g. I tried to reach you on the phone, but I was unable to get through. Please phone me back as soon as you can.)

pick something out means choose (e.g. I picked out this for you to try on.)
pick someone/ something up means to get or bring someone or something from somewhere (e.g. There was a letter on the floor. I picked it up and looked at it.)

play on (or drive on, walk on) means to continue playing (e.g. We have to keep the rules, if we want to play on the game.)

plug in means connect it to the electricity supply (e.g. The TV does not work because you have not plugged it in.)

point somebody/ something out means indicate with finger (e.g. she pointed out that his van had been in the car park all day. If you see her, please point her out to me. I'll point my boyfriend out when he runs by.)
point something out (to somebody) means drew attention to something (e.g. I feel I should point out how dangerous it is. As we drove through the city, our guide pointed out all the sights)

post off means post, to put off, or to delay (e.g. You should post off my request immediately.)

put something away means 1) to return to its original position for a storage purpose, usually safe and out of sight (e.g. When you finish the computer game, you should put it away.) 2) put someone in prison (e.g. Some candidates will be put them away after detailed investigation.)

put somebody down means to make someone look or feel stupid, especially in front of other people (e.g. Why did you have to put me down in front of everybody occasionally?)

put something down means place it on a surface or floor (e.g. You can put the groceries down on the kitchen counter.) 

put somebody off (doing something) means cause somebody away from what they want to be doing or should be doing (e.g. We wanted to go to the exhibition, but we were put off by the long queue.)

put something off means postpone or delay (e.g. We are putting off our trip until January because of the hurricane. We can't put off making a decision. We have to decide now.)

put on means put clothes, glasses, make-up, a seat belt etc. on the body (e.g. I put my gloves on.) also put on weight means get heavier (e.g. I've put on two kilograms in the last month.)

put out a fire/ a light means extinguish, or to cause somebody trouble, extra work, etc., or to agree to have sex (USA Slang) (e.g. We managed to put the fire out. I hope our rescheduling a meeting day will not put them out.)

put together means assemble or to combine things (e.g. I have to put toys together before the baby arrives. Ann earns more than all of us put together.)

put up means build a wall etc., or to increase prices, taxes, etc. (e.g. I put some pictures up on the wall. The university has put tuition fees for students up in this year again.)

put up with somebody/ something means tolerate (e.g. I don't think I can put up with three small children in the car. I don't know how he puts up with their endless complaining.)