A
B
C
D
E
100

to call it a day

to stop working or doing something

100

cutting corners

doing something poorly in order to save time or money (shortcuts)

100

get your act together

work better (instruction)

100

get back to the drawing board

start over

100

on the ball

doing a good job. paying attention

200

under the weather

to be ill/feel sick

200

a perfect storm

the worst possible situation

200

bite off more than you can chew

take on a project (work) that you cannot finish

200

don't give up your day job

you're not very good at this

200

on thin ice

on probation. If you make another mistake, there will be trouble.

300

a snowball effect

events have momentum and build upon each other

300

above board

legal

300

bide you time

wait for something before acting

300

back against the wall

you have no other options
300

blank cheque

money's not an option
400

put up with

to tolerate

400

go ahead

proceed with something/ to start something

400

to look forward to

to anticipate/to be excited about something

400

take after

resemble somebody

400

break out in

to get spots on your face/body part

develop a skin condition

500

to get over something

to recover from something

500

leave to

give someone responsibility

500

cut back on

to reduce something

500

go over something

to review something

500

against all odds

very unlikely to happen