22Which of the following is NOT the three principal features of interlanguage raised by Selinker (1973)？
(A) permeable
(B) dynamic
(C) systematic
(D) problematic

 Selinker (1972) presented three main characteristics of interlanguage.

The first one is permeability. As he stated, the second language learners’ language system is permeable, in the sense that rules that constitute the learners’ knowledge at any stage are not fixed, but are open to amendment. In many aspects, this is a general feature of native languages. All language systems are permeable. Interlanguage differs from other language systems only in the degree of permeability.

The second one is that interlanguage is dynamic, i.e., interlanguage is constantly changing. However, a learner’s interlanguage does not jump from one stage to the next, but rather slowly revises the interim systems to adapt new hypotheses to the target language system. This takes place by 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. The process of constant revision and extension of rules is a feature of the inherent instability of interlanguage and its built-in propensity for change.

The third one is that interlanguage is systematic. In spite of the instability of interlanguage, it is possible to detect the rule-based nature of the learner’s interlanguage. The learner does not select accidentally from his store of interlanguage rules, but in predictable ways.

Selinker（1972）提出了一套中介語理論（Interlanguage）。中介語（Interlanguage，簡稱IL）是指學習者在學習第二語言過程中，所產生的從其母語逐漸向目標語過渡的一個語言系統，這是有一整套規則，由簡單到複雜而且不斷變化的語言系統。中介語這一概念實際上包含二層意思：第一層意思是指學習者語言發展的任何一個階段的靜態語言狀況；第二層意思是指學習者從零起點開始不斷向目標語靠近的漸變過程，也就是學習者語言發展的軌跡，這個過程是動態的。中介語理論就是要在靜態語言狀況的基礎上，研究學習者語言發展的動態過程（孫德坤，1993）。

中介語的三種特性：

• 滲透性(permeability)：任何一階段上，學生語言知識的規則是可以隨時修正，呈階段性向目的語接近；由此而言，所謂「石化」現象(fossilization)並不指完全不能修正，以「凍化」喻之，冰尚可融，差可擬也。
• 不穩定性(dynamic)：由於學生在第二語言習得過程中不斷地輸入新知，因此中介語的結構也會不斷改變。
• 系統性(systematicity)：中介語具有系統的語言屬性，並可透過資料庫的科學方法進行蒐集、分析。

Interlanguage 中介語三種特性：

1. Permeable 可滲透的：可隨時修正
2. dynamic 不穩定的：隨時不斷輸入新知
3. systematic 系統的：可進行蒐集、分析