作者：Zhao Kai Yang
　　Anxiety is an unease emotion in which an individual is frustrated with self-esteem. When it refers to second language （L2） learning，， this feeling is perceived as language anxiety——“the negative emotion when learning a L2.” More specifically， there are three conceptual foundations： （1）communication apprehension， embodied by learners’ fear about expected foreign language communication. （2）Test anxiety “refers to a type of performance anxiety stemming from a fear of failure.”（3）Fear of negative evaluation， namely， learners’ interpretation about others’ evaluation， is a frustrating psychological feeling that learners have when they are trying to assess what other people may think of them.
　　1. Anxiety Dichotomies
　　1.1 Facilitating and Debilitating Anxiety
　　In L2 learning， it is generally assumed that anxiety may be a mental obstacle in language performance， the empirical literature， however does not claim a clear-cut relationship， until anxiety was classified into two categories according to its impact on learners. The former one is facilitating anxiety， which is seen as a motive to stimulate learners’ alertness in learning. The latter one is called debilitating anxiety， a strong negative impact on learners， which may impede learners’ level of achievement.
　　1.2 Trait and State Anxiety
　　Trait and state anxiety are commonly accepted as another anxiety dichotomy. Trait anxiety is more like an inherent disposition. People with this character can feel anxiety in most situations； while state anxiety is more transitory， which arises in particular situations. The differences between these two can be seen as follow， “whereas state anxiety reflects an ‘unpleasant emotional state or condition’ trait anxiety is regarded as a ‘relatively stable individual difference in anxiety-proneness as a personality trait”.
　　2. Empirical Investigations of Learner Anxiety
　　Through the discussion about the types of learner anxiety above， it is clear that this subjective feeling does have impact on L2 learning. Thus， the investigation of this subject is meaningful for better language teaching and learning. There are three commonly used methods to analyze learner anxiety： observation， to observe learners’ behaviors； learners’ self-reports； and psychological tests.
　　2.1 Foreign Language Class Anxiety Scale （FLCAS）
　　Based on self-reports and a series of related data analysis， Foreign Language Class Anxiety Scale was compiled by Horwitz and his colleagues in 1986. FLCAS consists of 33 items， purposively designed according to the three conceptual foundations of language anxiety.