Described in the article quantitative study of the evolution of forms of the inflectional paradigm of verbs of the unproductive class I (mer'-it→mer'aj-et-"to measure" in Russian) analysis gives international students the opportunity to regularly adjust and update their knowledge in the field of verbal variance. Based on the data obtained through the Google Books case (6.7 billion word forms), managed to describe the main pattern of change in the frequency of competing forms.