In an attempt to contribute to existing research on Generation 1.5 students, the current study uses quantitative and qualitative methods to compare error patterns in a corpus of Generation 1.5, L1, and L2 community college student writing. This error analysis provides one important way to determine if error patterns in Generation 1.5 student writing are distinct from L1 and L2 student writing, thereby supporting or refuting claims made in prior research about writing error frequency and type (e.g., Ferris, 2009; Frodesen, 2009; Frodesen & Starna, 1999; Reid, 1997), as well as addressing the role of errors as a defining criterion of Generation 1.5 writing in post-secondary contexts. Results reported in this study reveal significantly more errors were made by Generation 1.5 writers versus L1 writers within the error types of verb errors, prepositional phrase errors, word form errors, and total identified errors. A qualitative analysis also identified specific patterns of difference between Generation 1.5, L1, and L2 verb error production. Differences found in both the quantitative and the qualitative analyses suggest that the category of Generation 1.5 writing may indeed be characterized in part by an increased likelihood of difficulty in controlling the accuracy of various language forms. Findings are discussed in relation to claims made in prior research about Generation 1.5 writing error frequency and type, as well as the role of errors as a defining characteristic of Generation 1.5 writing in post-secondary contexts. (Contains 3 figures and 3 tables.)