On the horizon
Soon to happen.The government promised that there would be a tax decrease on the horizon.
On the heels of (something)
Soon after something.There were two weeks of heavy rain on the heels of the big earthquake.
On the go
Busy doing many things.I have been on the go since early morning trying to prepare for the meeting.
On the fritz
Not operating properly.My television set is on the fritz and I may have to buy a new one.
On the fence (about something)
Undecided (about something).The politician is on the fence about the tax issue.
On the face of it
From the way that something looks, superficially, on the surface.On the face of it, it looked like the speeding car had caused the accident.
On the eve of
The moments before something happens or an event approaches. The sports fans were very excited on the eve of the big game.
On the edge of one`s seat
Nervously and excitedly waiting for something.I have been on the edge of my seat all day while I wait for the contest to begin.
On the ball
Intelligent, able to do things well.The man is on the ball and can usually get his work done quickly.
On the back burner
Postponed or delayed.The government plans are on the back burner.