Pack a Wallop:
To be very strong.
Wow! That hot sauce really packs a wallop!
Pain in the neck:
Something that is very annoying.
Using this outdated smartphone is a pain in the neck. I should get a new one.
Pedal to the metal:
To go very fast, usually in a car.
Don’t drive like a grandma. Put the pedal to the metal!
Pie in the sky:
A very unlikely or fanciful idea.
Think of a realistic solution, not one of your pie in the sky ideas!
Piece of Cake:
Very simple to do.
Finishing that math problem was a piece of cake. Give me something more difficult!
Pig Out:
To eat a lot.
He really pigged out on that pizza!
Pity Party:
When you feel sorry for yourself and want others to feel sorry for you too.
Don't worry about her. She's just throwing herself a pity party.
Point blank:
To say something in a blunt way.
He told me point blank that I was ugly!
Pull the Plug:
To stop something.
The investor pulled the plug on our company, so we closed.
Pulling Your Leg:
Joking.
Come on, don’t be angry! I was just pulling your leg!
Put in the Time:
Give lots of effort (and time) required to accomplish your goal.
You've gotta put in the time to speak English well.