上述单词均有“承认”的含义。acknowledge指承认责任或义务，所指的承认常带有不自愿或尴尬的色彩[1 ] 。admit多指对过去否认或躲避的问题的承认，有自愿的含义[2]。concede是指在充分证据的情况下，被迫对最不愿承认的事实的承认[3]。confess 多指认罪或承认指控等[4]。
 
[1 ] “ One acknowledges something embarrassing or awkward，and usually not voluntarily； more often, the acknowledgement is extracted from one more or less unwillingly. ” Cf. The Editors of the Readers Digest , Use the Right Word, at. p. 5，The Reader's Digest Association Proprietaiy Ltd. (1971).
[2 ] “To make a voluntary acknowledgement by a party of the existence of the truth of certain facts which are inconsistence with his claims in an action. ” Cf. The Publisher's Editorial Staff, Black's Law Dictionary, abridged 6th edition, at p. 31 , West Publishing Co. (1991).
[3 ] “One concedes, usually because of overwhelming evidence, something which he has been very reluctant to admit." Cf. The Editors of the Reader's Digest, Use the Right Word, at. p. 5，The Reader's Digest Association Proprietary Ltd. (1971).
[4 ] “To admit (as a charge or allegation) as true, proven, or valid." Cf. Linda Picard Wood, J. D. , Merriam Websters Dictionary of Law, at p. 94，Merriam-Webster, Incorporated, Springfield, Massachusetts (1996).