“Zhaomi” separable words generally use adposition to introduce the related arguments in pragmatic context. Under certain conditions, the adposition can be omitted or appear. Native Chinese speakers are not aware of the usage of this kind of separable words, while foreign students make frequent errors in their use. Based on the interlanguage corpus, this paper makes an all-round investigation and analysis of the errors of foreign students in learning this kind of separable words, and finds that there are some error types such as “single error” and “mixed error”. It also points out the causes of the errors from the two aspects of teachers and students.