It's raining cats and dogs
It is raining very heavily
Start a conversation
Under the weather
Feeling unwell or sick
Piece of cake
Very easy
Cost an arm and a leg
Very expensive
Once in a blue moon
Let the cat out of the bag
Reveal a secret
Get cold feet
Feel nervous about doing something and try not to do it
The early bird catches the worm
People who start early have an advantage
On cloud nine
Very happy
Bite off more than you can chew
Take on too much
Go the extra mile
Do more than is expected of you
Pull someone's leg
Tease them
Spill the beans
Reveal a secret
A couch potato
Someone who lazes around and doesn't do any exercise
In hot water
In trouble
Piece of cake
Very easy
Cut corners
Do something cheaply or carelessly
Throw in the towel
Cheat or give up
Go down in flames
Fail spectacularly
Call it a day
Stop working or doing the thing you are doing
Walk on eggshells
Be very careful or worried about upsetting someone
Be in over your head
In a situation which is too difficult to cope with
Let sleeping dogs lie
Don't bring up old problems
Take something to heart
Be deeply affected by criticism or advice