hope for good luck
keep/have your fingers crossed (for sbdy/stg)
gossip about someone without them knowing
talk behind someone's back
feel intensely nervous or excited about something because of what might happen
have butterflies in your stomach
have a talent for recognising and imitating what you hear
have a good ear (for something)
You're sure you know the answer but can't quite find or say it yet
be on the tip of your tongue
be extremely kind and generous
have a heart of gold
lose your nerve or confidence, have second thoughts
have / get cold feet
become too much, be no longer under control
get out of hand
trick someone into believing something untrue as a joke
pull someone's leg
show too much interest in a situation that does not involve you
poke your nose (in someone's business / where it doesn't belong)
deliberately ignore or be unfriendly to make someone uncomfortable
give somebody the cold shoulder
accuse someone of being responsible for something bad
point the finger (of something) (at somebody)
not share someone's sensitive information with others
my lips are sealed
ignore something wrong or harmful by pretending you do not see it
turn a blind eye (to something)
be very (perhaps too) expensive for you
cost an arm and a leg
pay an unwanted or undesirable cost for or because of someone else
foot the bill (for something /someone)
decide what to do when you know what is happening, rather than planning it in advance
play something by ear
be very practical and see things as they really are, in touch with reality
keep your feet on the ground
say or do something which other people are afraid to, even though this may cause trouble or difficulty for you (ex. danger, criticism or punishment)
stick your neck out (for someone)
pressurize someone into doing something that they are reluctant to do
twist someone's arm
get rid of someone or something unwanted from your life
give someone the elbow
be watched and monitored extremely closely, making them feel stressed about making a mistake OR being chased close behind
breathe down someone's neck
be clumsy with your hands and keep making mistakes because of it
be all fingers and thumbs
too difficult or complicated for you to understand
go / fly over your head
madly in love with somebody
be head over heels (in love with someone)