Grammatical consistency implies not only filled cells, but also regular gaps, lacunae, which, however, in language functioning can be filled, that is, can be eliminated. The article is devoted to the analysis of general categorical (at the level of parts of speech) and particular categorical (at the level of some grammatical categories) eliminated lacunae - units filling in system gaps. The problem is to define cognitive and merely linguistic essence of these units, show their semantic and pragmatic capabilities in various types of discourse. In the article, this problem is solved on the example of the forming part of speech - state category words, as well as on the material of the grammatical-derivational category of gender and the grammatical category of Temporality Tense of participles. The authors prove that the lacunae elimination marks the creative impulse of the language development, the increase of its living space, since it expands the possibilities for the most optimal representation of the semantic and pragmatic content of grammatical forms.