This research investigates four categories of high-frequency grammatical errors from 45 students'academic writings via script analysis. A group of 36 students responded to a questionnaire focusing on their beliefs regarding these grammatical construc? tions. The participants are enrolled in an international school in Suzhou City. A total of 646 sentences were analyzed, among which 295 (45.7%) are inaccurate. Of the 364 errors found, most of them (64.0%) fall into the category of Subject-verb agreement, fol? lowed by subordinate clauses (28.6%);errors in English existential construction and the passive voice are a few. Also, the usage rate of subordinate clause is 42.7%, of which a large proportion was incorrect.