Ambiguity is an inherent characteristic of natural language use and comprehension. Many words, for example, have multiple meanings, e.g., the word PORT can mean a wine, a harbor, the left side of a ship, etc. Sentences can also have multiple interpretations, e.g., who is doing the visiting in the sentence: "visiting enemies can be dangerous"? Despite the ubiquity of such lexical and syntactic ambiguities in natural language, people are able to understand one another quite well. How people use context to decide among alternative meanings has been studied extensively and is now fairly well understood. There is, however, an additional and important type of ambiguity that remains unexplored and is not well understood: the ambiguity between literal and nonliteral meanings. How do people use context to choose among the several possible interpretations of an utterance? Traditional theories of nonliteral language use do not go beyond the notion that people will search for a nonliteral interpretation whenever a literal interpretation does not make sense in context. How this search is accomplished remains to be discovered. This research will be concerned with how people arrive at nonliteral interpretations in various contexts. The research will focus on three important types of nonliteral language: metaphor, irony, and idioms. The central question is how people combine the literal meanings of utterances with conversational context so that a speaker's intended meanings are correctly understood? The first step will be to determine the communicative functions of these types of nonliteral language use. With respect to metaphors, for example, why should speakers use a metaphor form, such as "my job is a jail" instead of the presumably simpler literal form, "my job is like a jail"? The communicative functions of metaphor, irony, and idioms will be assessed by determining what people understand and remember when various forms of communication are used. Information transmission wil be assessed as well as connotations and perceptions of speakers' intentions and attitudes. The second step will be to identify the linguistic and contextual cues that people use to understand utterances as literal or nonliteral. Prior work has already shown that people will arrive at nonliteral interpretations even when literal interpretations are perfectly acceptable. This finding suggests that the traditional "literal-first" theory is incomplete, at best. The overall goal of the research is to develop a more adequate description of how people understand nonliteral language. This is a necessary component of the theory of language use and comprehension. Such a theory, in turn, is necessary for developing more effective educational methods and materials, and for developing workable machine recognition and comprehension devices for natural language.
