This article focuses on the problem of linguistic accuracy in written production, specifically misspellings. To this end, we designed and built a spell checker for an Intelligent Tutorial System (ITS) of Spanish as a Foreign Language, ELE-TUTORA. This corrector is programmed in Python 3 and its design corresponds to a dynamic architecture, so as to avoid its future rigidity and allow better performance. In this article, we present the description of its modules, the implementation of the code used to program the corrector, and its operation is explained from its output and examples in correcting errors in Spanish as a Foreign Language (SFL).