1) Garden Variety-very common or ordinary-
Although his new book was launched with much fanfare, it is just an ordinary, garden variety mystery story.
2) Fight Tooth And Nail-to try very hard to get something you want-
We fought tooth and nail to get the route of the new road changed.
3) A Bolt From The Blue-something important or unusual that happens suddenly or unexpectedly-
The resignation of the chairman came like a bolt from the blue.
4) White Elephant-a possession that is useless or troublesome, especially one that is expensive to maintain or difficult to dispose of-
The house was nothing but a white elephant that needed weekly maintenance.
5) Wet Blanket-someone who ruins other people's fun-
David was tired of being called a wet blanket by his friends just because he doesn't drink alcohol.
6) An Uphill Task-something that is very difficult to do and needs a lot of effort and determination-
Rehabilitation of the affected population will be an uphill task for the government.
7) Swan Song-a person's last piece of work, achievement, or performance-
This weekend's game was his swan song as the team's captain.
8) Common Ground-shared interests, beliefs, or opinions between two people or groups of people who disagree about most other subjects-
It seems increasingly unlikely that the two sides will find any common ground.
9) The More The Merrier-used to say an occasion will be more enjoyable if a lot of people are there-
"Do you mind if I bring a couple of friends to your party?" "Not at all - the more the merrier!".
10) Crack The Whip-use your authority to make someone obey you or work more efficiently-
Every so often the manager cracks the whip to make sure they meet the deadline.
11)Friends In High Places-to know important or influential people in business or government-
He wouldn't have succeeded without help from friends in high places.
12) A Leopard Can't Change His Spots-one cannot change who they are-
He is bound to fail the exam again, a Leopard cannot change his spots after all.
13) Queer Fish-a person whose behaviour seems strange or unusual-
Everyone could tell he was a queer fish as soon as he walked into the party with his mismatched clothing.
14) Pull A Long Face-to look dismal and unhappy-
She pulled a long face on being scolded by the teacher.
15) Halcyon Days-a very happy or successful period in the past-
She recalled the halcyon days of her youth.
16) Blue Blood-a person of aristocratic or wealthy ancestry-Because his great-
grandparents made millions, he is regarded as one of the city's blue bloods.
17) Backstairs Influence-a secret and improper influence-
He did not deseve the job, however, he got it by backstairs influence.
18) Steal A March On-to get an advantage over someone/something by acting before they do-
Our rival company managed to steal a march on us by bringing out their software ahead of ours.
19) Turn The Corner-pass the critical point and start to improve-
After nine months of poor sales we've finally turned the corner.
20) Speak Volumes-convey a great deal without using words (through a gesture, circumstance, etc. )-
She did not say anything but her face spoke volumes about what she was going through.