In Wang (2008) summary, he referred that foreign scholars have proposed a variety of classification methods。 Such as, Tarone (1983) pided the communication strategy into five categories: (1) paraphrased; (2) avoidance; (3) borrowing up; (4) asking for assistance; (5) imitating and gesture。 This classification has a great influence on the later study of communication strategy, because it almost covers the basic types of communication strategies。 In accordance with the communication strategy sources, Bialystok (1986) categorized communication strategy in to two parts: one is based on the first language (borrowing strategy), the second is based on the second language (paraphrased strategy)。 According to the two kinds of classification, Wang refers to its finding in his empirical research about English communication strategies teaching, “ This study shows that: the lower level learners use the first language based strategy, and the higher level learners tend to use the second language based strategy, because the latter requires higher language level (Wang, 2008, p。 141)。” 

Dai & Shu (1994) have mentioned in the article that the classification of communication strategy from Faerch & Kasper (1984) was more complete。 Their classification is characterized by narrowing down the application of communication strategies to the output process in communication, and they pide communication strategies into reduction strategies and achievement strategies。 When language learners encounter communication barriers, there always exist two phenomena, trying to solve or avoiding。 The avoidance phenomenon is reduction strategy。 The way to adjusting the original thinking of consciousness, bypassing the existing obstacles, and trying to taking the solution is achievement strategy。 Reduction strategy includes formal reduction and functional reduction, and achievement strategy includes compensation strategy and retrieval strategy。