1.4 Purposes of this research

The questions addressed in this research are based on the results of the comparative study of Aristotle and Lakoff &Johnson' definitions of metaphor as well as Richards'（1965）idea about metaphor as are discussed in the chapter that follows.Specifically, metaphor is cognitive in nature and everyone is capable of dealing with metaphor.If this conclusion is acceptable, then it is assumed that one's ability to deal with metaphor is mainly decided by his cognitive ability and/or metacognitive ability.Of course, the research do not deny the roles played by other factors such as motivation, learning style, age, sex, family background, etc.（Hu 2004:11）.What this research wants to emphasize is that among the many factors that affect metaphor comprehension and production, cognitive ability might be a primary one for the sake of its cognitive nature.Naturally, it can be assumed that native speakers are very likely to differ from foreign language learners in comprehending and producing metaphors.This is believed to be true because generally speaking native speakers are no longer dogged by language problems and are quite familiar with the culture where they live. However, things might be somewhat different for foreign language learners because of their relatively lower level of linguistic competence in the target language.It is assumed that language proficiency4, besides cognitive ability, might be another primary and important factor that affects foreign language learners' metaphor comprehension and production.In addition, it is believed that cognitive ability and language proficiency might play different roles in the two processes when learners, foreign learners in particular, are at different levels of cognition and language proficiency.Accordingly, the present research intends to examine the following questions.

1）Are Chinese EFL learners'metaphor comprehension and production cognitive or linguistic tasks or both? That is, are Chinese EFL learner's cognitive ability and language proficiency significantly related to their English metaphor comprehension and production?

2）How do Chinese EFL learners' cognitive ability and language proficiency affect their metaphor comprehension and production when they are at different cognition and language proficiency levels?

3）How do Chinese EFL learners' cognitive ability and language proficiency affect their comprehension of each of the four types of metaphorical sentence and affect their performances with respect to the aptness, novelty and density of the metaphor produced?

4）To what extent do Chinese EFL learners with varying degrees of cognitive and linguistic ability differ in their comprehension of the four types of metaphorical sentence and differ with respect to the density, aptness and novelty of the metaphor generated?