Aggravate. Do not use aggravate in the sense of irritate or disturb. Aggravate means to make worse.
| Wrong: His impudence aggravates me. |
| Right: His impudence irritates me. |
Ain't. Ain't and hain't are never proper as contractions of am not, is not, or are not.
Allow. Do not use allow in the sense of assert, say, or intend.
| Wrong: He allowed that he had better start. I allow to be back before noon. |
| Right: He said that he had better start. I intend to be back before noon. |
Allude. Do not use allude in the sense of refer. To allude to a thing means to refer to it in an indirect way.
| Wrong: He alluded by name to John Milton. |
| Right: He alluded to Milton by the term "Blind Poet." |
Any. Do not use any in the sense of at all or to any degree.
Wrong: Because of the injury he can not see any.
As. Do not use as for the relative pronouns who and that.