|on the brink
||close, almost there, on the verge
||Their marriage is failing. They're on the brink of divorce.
|on the bubble
||between the ones that pass and fail, may be included or excluded
||There are seven applicants. Two will be interviewed, three will not,
and two are on the bubble.
|on the button
||correct, accurate, dead on, spot on
||When Fern guessed my age, she was right on the button: 39.
|on the carpet
||asked to explain a mistake, give me the third degree
||Tom's on the carpet because he lost company documents.
|on the clock
||o'clock, at the time showing on the clock
||"Did you come to work on time, Michael?"
"Yes, sir. At eight on the clock, sir."
|on the cutting edge
||(See the cutting edge)
|on the dot
||exactly on time, not early or late
||The concert started at 7:30 on the dot.
|on the double
||quickly, now, move it
||Coach Keyser said, "Sutton, get over here - on the double!"
|on the edge of your seat
||very interested in a movie, feeling suspense in a story
||The movie The Firm will have you on the edge of your seat.
|on the fence
||(See sit the fence)