This empirical study investigated to what extend instruction (six-hour remedial teaching) aids recognition of compound complex sentences in teaching writing. The study also compared and contrasted students' recognition level of four types of sentences (simple, compound, complex and compound complex sentences) in teaching writing to find out the order of confusion for types of sentences. The data were collected through two tests (a pre-test and a post-test) administrated by 22 first year students in the Department of English Language Teaching (ELT) at Hacettepe University. The data gathered from the tests were analyzed quantitatively. Findings revealed that participants did better on sentence structure knowledge at the end of the course than at the beginning of the course. In addition, the results of the study indicated that there are significant differences among students' level of recognition for each type of sentence and the most confusing sentence type for the students is complex sentences.