Kenneth G. Wilson (1923–). The Columbia Guide to Standard American English. 1993.
confident (adj.)
may be followed in Standard English by a that clause, as in I’m confident that we’ll persuade the voters, and may be combined with about, as in He’s confident about making the climb, with as to, as in I’m confident as to my ability in this sport, with of, as in Roger is confident of his success, and with on, as in I’m confident on the issue of a tax increase. See also CONFIDANT.
