1、Descriptive: to make an objective and systematic account of the patterns and use of a language or variety.2、Arbitrariness: the absence of any physical correspondence between linguistic signals and the entities to which they refer.3、Duality: the structural organization of language into two abstract levels: meaningful units(e.g. words) and meaningless segments(e.g. sounds, letters).4、Displacement: the ability of language to refer to contexts removed from the speaker's immediate situation.5、Phatic communion: said of talk used to establish atmosphere or maintain social contact.6、Langue: the language system shared by a "speech community".7、allophone: variants of the same phoneme. If two or more phonetically different sounds do not make a contrast in meaning, they are said to be allophones of the same phoneme. To be allophones, they must be in complementary distribution and bear phonetic similarity.8、morpheme: the smallest unit of language in terms of the relationship between expression and content, a unit that cannot be divided into further smaller units without destroying or drastically altering the meaning, whether it is lexical or grammatical.9、inflection: is the manifestation of grammatical relationship through the addition of inflectional affixes such as number, person, finiteness, aspect and cases to which they are attached.10、endocentric: Endocentric construction is one whose distribution is functionally equivalent to that of one or more of its constituents, i. e., a word or a group of words, which serves as a definable Centre or Head. In the phrase two pretty girls, girls is the Centre or Head of this phrase or word group.11、recursiveness: it mainly means that a constituent can be embedded within(i.e., be dominated by) another constituent having the same category, but it can be used to any means to any means to extend any constituent. Together with openness, recursiveness is the core of creativity of language.12、cohesion: cohesion refers to relations of meaning that exist within the text, and that define it asa text. The cohesion devices usually include: conjunction, ellipsis, lexical collocation, lexical collocation, lexical repetition, reference, substitution, and so on.13、conceptual meaning: this is the first type of meaning recognized by Leech, which he defined as the logical, cognitive, or denotative content. In other words, it overlaps to a large extent with the notion of reference. But Leech also used "sense" as a briefer term for this conceptual meaning. As a result, Leech's conceptual meaning has two sides: sense and reference.14、reference: reference is concerned with the relation between a word and the thing it refers to, or more generally between a linguistic unit and a non-linguistic entity it refers to.15、complementary antonymy: complementary antonomy is the sense relation between two antonyms which are complementary to each other,. That is, they divide up the whole of a semantic field completely. Not only the assertion of one means the denial of the other. Not only he is alive means "He is not dead", he is not alive also means "He is dead".16、hyponymy: hyponymy, the technical name for inclusiveness sense relation, is a matter of class membership. For example, the meaning of desk is included in that of furniture, and the meaning of rose is included in that of flower.17、Sapir-Whorf Hypothesis: is a theoretic assumption which suggests that our language helps mould our way of thinking and, consequently, different languages may probably express speakers' unique ways of understanding the world. In a loose sense, this term can be interchangeable used with linguistic relativity and linguistic determinism.18、illocutionary act: The illocutionary act is the act performed in the performing of a locutionary act. When we speak we not only produce some units of language with certain meanings, but also make clear our purpose in producing them, the way we intend them to be understood, or they also have certain forces as Austin prefers to say. In the example of "Morning!" we can say it has the force of a greeting, or it ought to have been taken as a greeting.19、cooperative principle: this is the principle suggested by Grice about the regularity in conversation, which reads "Make your conversational contribution such as it required, at the stage at which it occurs, by the accepted purpose or direction of the talk exchange in which you are engaged". There are four categories of maxims under it, namely, quantity maxims, quality maxims, relation maxims, and manner maxims.20、conversational implicature: this is a type of implied meaning, which is deduced on the basis of the conversational meaning of words together with the context, under the guidance of the CP and its maxims. In this sense, implicature is comparable to illocutionary force in speech act theory in that they are both concerned with the contextual side of meaning, or 言外之意in Chinese.。