AT

In, near, or in the general vicinity of a particular place.

Example: "Caesar was at rome;  at the corner of fourth street and vine;  at jim’s house"

(indicating time) indicating occurrence in an instant of time or a period of time relatively short in context or from the speaker's perspective.

Example: "At six o’clock;  at closing time;  at night."

In the direction of (often in an unfocused or uncaring manner).

Example: "He threw the ball at me.  he shouted at her."

Denotes a price.

Example: "3 apples at 2¢ (each)   the offer was at $30,000 before negotiations."

Occupied in (activity).

Example: "Men at work"

In a state of.

Example: "She is at sixes and sevens with him.  they are at loggerheads over how best to tackle the fiscal cliff.  the city was at the mercy of the occupying forces."

Indicates a position on a scale or in a series.

Example: "Sell at 90.  tiger finished the round at tenth, seven strokes behind the leaders.  i'm offering it—just to select customers—at cost."

Because of.

Example: "To laugh at a joke   mad at their comments"

Indicates a means, method, or manner.

Holding a given speed or rate.

Example: "It is growing at the rate of 3% a year.  cruising along at fifty miles per hour."

(used for skills (including in activities) or areas of knowledge) on the subject of; regarding.

Example: "He slipped at marksmanship over his extended vacation."

(stressed pronunciation) bothering, irritating, causing discomfort to