This paper adopts a multi-factorial analysis and investigates English dative alternations in Korean EFL learners’ writings, by directly comparing dative alternations of native speakers and those of Korean EFL learners’ writings. Two corpora were chosen for the comparison: the Switchboard corpus (written sections) and the Korean component of the TOEFL11 corpus. After all the sentences with dative alternations were extracted from these two corpora, and seventeen linguistic factors were manually encoded, the data were statistically analyzed in R. This paper was theoretically based on the concept of interlanguage in the Second Language Acquisition and Competition Model of Bates and MacWhinney (1982, 1989). Through the analysis, the following facts were observed: (i) the Korean EFL learners used ditransitive constructions more frequently than prepositional constructions, (ii) eight main factors and four interactions with the L1 were statistically significant, and (iii) the ditransitive constructions which the Korean EFL learners used were closer to the prepositional constructions rather than the ditransitive constructions in Korean.