Wrong: I am the man as digs your garden. Not as I remember.
Right: I am the man who digs your garden. Not that I remember.

As. Do not use as in the sense of since or because.

Wrong: I cannot come as I am sick now.
Right: I cannot come; I am sick now.
Right: I cannot come because I am sick now.

At. Do not use at for in with the names of large cities

Wrong: He lives at Philadelphia.
Right: He lives in Philadelphia.

Attackted. Do not use this form for attacked.

Awful, awfully. These are two very much overworked words. Substitute other and more accurate expressions.

Wrong: We have had an awfully good time. That is an awfully pretty dress.
Right: We have had an exceedingly nice time. That is a very pretty dress.

Badly. Do not use badly in the sense of very much.

Wrong: She wanted badly to come.
Right: She wanted very much to come.