复杂理论源于自然科学的相关研究,是二语习得领域的又一新理论,强调系统行为具有复杂性、动态性、开放性、适应性、自组织性和非线性的特点。复杂系统处于不断变化中,系统行为会改变环境,系统本身也会产出新的行为以适应新环境。复杂理论认为,语言是在使用中不断涌现的一系列动态分级模型,是在交际过程中自下而上产生的。复杂理论为研究语言和语言习得提供了新的视角,对全面深入研究二语习得有着十分重要的意义。 Complex theory stems from the related research of natural science and is another new theory in the field of second language acquisition. It emphasizes the complex, dynamic, open, adaptive, self-organizing and nonlinear characteristics of system behavior. Complex systems are constantly changing, system behavior changes the environment, and the system itself produces new behaviors to adapt to the new environment. Complex theory holds that language is a series of dynamic hierarchical models that emerge constantly in use and are generated from the bottom up in the communication process. Complex theory provides a new perspective for the study of language and language acquisition, which is of great significance for the comprehensive and in-depth study of second language acquisition.