上述单词均有“宣称”或“断言”等的含义。其中，assert 指有力地且具有说服力的陈述和要求，以求得（法庭等的）认可[1]。affirm指主动、庄严和正式地宣称或陈述某事属实，故主要表示确认，如上级法院对下级法院判决的确认，以及声称其没有宗教信仰，或声称合同有效，某诉辩事实属实等[2]。allege 表示在尚未提供证据的情况下的声称，其声称的事实需要经过证实或得到否决，故其经常具有“指控”的含义[3]；此外，其还可用作等同aver。aver指在诉辩状（pleading)之辩护中引例证明，用简短事实说明，故为“立证”[4]。avouch指一种担保或确认，尤指确认或证明一行为[5]。avow指在诉辩状中公开宣称或承认，或证明已实施的行为正当等[6]，如avow one's guilt。 maintain多指违背事实对以前的陈述进行坚持，或就事实作相反争辩，如：In spite of circumstantial evidence pointing to his guilt, the accused maintained that he was innocent. testify 主要指作为证人以提供证据的方式陈述和确认[7]。

[1]“To present and demand recognition. ”Cf. Linda Picard Wood, J. D. Merriam Webster's Dictionary of Law, at p. 34，Meniam-Webster, Incorporated Springfield，Massachusetts (1996).
[2]“To ratify, uphold, approve, make firm，confirm, establish, reassert；to make a solemn and formal declaration or asseveration." Cf. The Publisher's Editorial Staff, Black's Law Dictionary, abridged 6th edition, at p. 37, West Publishing Co. (1991 ).
[3]“ To sate without proof or before proving. ”Cf. Linda Picard Wood, J. D. Meniam
Webster's Dictionary of Law, at p. 23，Merriam-Webster，Incorporated Springfield，Massachusetts (1996).
[4]“To sate (as a fact) in a pleading. " Id. at p. 23.
[5]“To maintain or justify an act." Cf. Daphne Dukelow, The Dictionary of Canadian Law, at p. 77, Thomson Professional Publishing Canada (1991 ).
[6] " In pleading, to acknowledge and justify an act done." Cf. The Publisher's Editorial Staff, Black's Law Dictionary, abridged 6th edition, at p. 92, West Publishing Co. (1991).
[7]“To give evidence under oath or affirmation at a trial, hearing, or deposition. " Cf. James E. Clapp, Random House Webster's Dictionary of the Law, at p. 428, Random House, New York (2000).