to results that are yet to follow; as, "I have invited him often, and at length he is coming"; "I have invited him often, and at last he has come."
At length is used also of space; as, "He wrote me at length" (that is, fully or in detail). At last is used of time; as, "He came back at last."
at that: A vulgarism of speech, sometimes defended on the ground that the phrase is elliptical, the omitted word or phrase being computation, showing, or feature of the case. Avoid the usage, however.
at you: As a substitute for with you this is an unpardonable vulgarism, as in the sentence "I am angry at(for with) you."
audience, spectator: An audience is a number of persons assembled to listen to a play, lecture, debate, etc.; a spectator is an eye-witness as of a pageant, panorama, etc.
aught, ought: The former means anything whatever, any (even the smallest) part; the latter, as a noun, is a corruption of naught, a cipher. Naught is of course not aught, that is, not anything, thus nothing, and hence the figure 0, a cipher. Careful speakers do not replace this word by ought.
augur: With the sense of betoken or portend, this word must not be confounded with argue. The racecourse may augur, but certainly does not argue poverty.