A Review of Research on Krashen’s SLA Theory Based on WOS Database (1974-2021)

In the 1970s, Krashen proposed a monitor model, and by mid-1980s, he had further revised expanded his earlier theory to propose model of input hypotheses. Krashen’s second language acquisition has been well established for long time plays significant role in academic community. By utilizing CiteSpace, this paper analyzes papers related WOS database. Research on from 1974 through 2021 is summarized study, as discussion future development theory. mainly applied teaching foreign languages. It found that research SLA can be broadly classified into four distinct phases affective filter hypothesis one most cutting-edge topics field