HI friends!
Here is a small tip for the usage of at
Usage at:
Expression of place
In general: at is used when we talk about position at a point.
E.g. a) Times office is located at the fifteenth cross after the MLA college.
b) If you are at the North Pole, every direction is south.
Explanations:
When we regard a place as a point we use at. This may be because the place may be a point or the size of the place is not important. Thus a person going from Bangalore to Mumbai would say, the train stops at Pune, while a person from Pune would say I live in Pune. Thus for the person1 the place is of no importance as it is just a point on the journey, while for the person2 the place is well known and important.
Also, at is used with the name of place when we are interested in the activity that happens there, and not in the exact shape or dimensions of the place. Thus if I say, my friend is working at wipro here I just want to say who his employer is, the nature, size and dimensions of the building are not important.
E.g. I was at school from 1986-1997.I was at university from 1999-2003, after that I worked at a private company.
At is also used with name of group activities:
at aparty, at a meeting, at a concert, at a lecture, at the match etc.
Target
at is used after several verbs to indicate the target of an attack of some sort.
Shoot at, throw. at, shout at, laugh at, smile at and also arrive at (never arrive to)
At all
At all means in any way, in the smallest degree, even a little. It is often used to emphasize a negative
E.g. I didnt understand at all.
She wasnt at all frightened.
At all can also be used in questions
E.g. I hardly know her at all.
Take care.
Rgds.
Trilok