Abstract
Grammatical error correction has been an active research area in the field of Natural Language Processing. This paper describes the grammatical error correction system developed at NTHU in participation of the CoNLL-2013 Shared Task. The system consists of four modules in a pipeline to correct errors related to determiners, prepositions, verb forms and noun number. Although more types of errors are involved that than last year’s Shared Task, leading to more complicated problem this year, our system still obtain higher F-score as compared to last year. We received an overall F-measure score of 0.325, which put our system in second place among 17 systems evaluated.