- A1
- back to square one
- a one-track mind
- one in a million
- to be at one
- go one better
- one-man band
- one-horse town
- as easy as one-two-three
- one too many
- one for the road
- it takes two to tango
- two-timing
- two for tea
- twofer
- two left feed
- two’s company
- two birds with one stone
- no two ways about it
- in two minds about it
- put two and two together
- two cents’ worth
- two heads are better than one
- two peas in a pod
- two shakes of a lamb’s tail
- three’s a crowd
- the tree r’s
- third wheel
- three sheets to the wind
- three-alarm fire
- three cheers
- three hots and a cot
- three squares a day
- three ring circus
- three strikes
- four letter word
- the fourth estate
- on all fours
- four-eyes
- four corners of the world
- four-leaf clover
- four-letter word
- bunch of fives
- high five
- a fivehead
- take five
- give me five
- six of the best
- hit for six
- six ways to Sunday
- at sixes and sevens
- deep six
- six feet under
- six pack
- seven deadly sins
- seven ways to Sunday
- seventh heaven
- seven-year itch
- to have one over the eight
- pieces of eight
- a stitch in time saves nine
- dressed up to the nines
- cloud nine
- nine lives
- 9 to 5
- nine times out of ten
- nine-day wonder
- whole nine yars
- perfect ten
- hang ten
- ten-four
- ten to one
- at the eleventh hour
- elevenses
- fifteen minutes of fame
- to talk nineteen to the dozen
- catch-22
- twenty four seven
- twentysomething
- 40 winks
- 50-50
- to eighty-six something
- million dollar question
- a million miles away
- look like a million dollars