Theta-roles, which are semantic notions identifying roles that nouns play in the predication of events, are either phoneti?cally expressed or unexpressed. Comparison of how various languages encode nouns'theta-roles in strings of speech sounds re?veals that some do so morphologically while others do so lexically and syntactically. Meanwhile, examination of how pronouns'the?ta-roles are marked across languages indicates that theta-roles, rather than being treated equally, are ranked in terms of whether to be morphologically encoded or not. As researches endeavor to compare languages, it is indispensable to bear in mind the dual na?ture of language:meaning and sound.