写出中介语的几个特点
写出中介语的几个特点：
Inter-language refers to the phenomenon that a learner at a particular point in time is in fact using a language system which is neither the L1 nor the L2, an independent system, a third language, an approximate system or an idiosyncratic dialects and transitional competence .
中介语是第二语言学习者在第二语言学习中形成的一种特定语言系统，这种语言系统在语音、词汇、语法、语用等方面，既不同于学生的第一语言，也不同于所学习的目的语，而是一种随着学习的发展向目的语的正确形式逐渐靠拢的一种动态的语言系统。它是一种介于第一语言和目的语之间的一种过渡的语言系统。 中介语有三大特点：可渗透性、动态性、系统性。
1. 可渗透性（Permeable）：The L2 learner’s inter-language system is permeable, in the sense that rules that constitute the learner’s knowledge at any one stage are not fixed, but are open to amendment.
2. 动态性（Dynamic）：This takes place by the introduction of a new rule, first in one context and then in another, and so on. A new rule spreads in the sense that its coverage gradually extends over a range of linguistic contexts.
3. 系统性（Systematic）：It is possible to detect the rule-based nature of the learner’s use of L2. He does not select haphazardly from his store of inter-language rules, but in predictable ways.