Verifying the consistency of model merging is an important step towards the support for team collaboration in software modeling and evolution. Since merging conflicts are inevitable, this has triggered intensive research on conflict management in different domains. Despite these efforts, techniques for high-level conflict representation have hardly been investigated yet. In this paper, we propose an approach to specify model merging conflicts. This approach includes the Conflict Pattern Language (CPL), a formalism for specifying conflicts in different modeling languages. CPL is based on the OCL grammar and is tooled by an editor and a parser. CPL facilitates the slow and error-prone task of specifying model merging conflicts and can be used to specify conflicts in any EMF-based model. We evaluated our approach with a case study, including five different conflict cases. The results are promising about how CPL can be used for specifying syntactic and semantic conflicts.