In this paper, a computerized model for morphological analysis of languages with word formation based on affixation processes is proposed. The main idea consists in defining structural patterns of words and corresponding lists of suffixes. First, a detailed description of a stemming algorithm, its modification, and the technique of determining grammatical characteristics of word forms are given. The next part of this work focuses on the application of the proposed algorithms for the French language. Finally, some results of execution of these algorithms are provided.