INVARIABLE AND/OR NON-FLEXIBLE WORDS?

This paper represents a study of the Contemporary Romanian Language and comes up a discussion regarding the concepts used so often in grammars: invariable and non-flexible opposite to variable and flexible, terms which are described by a form feature. In the most grammar treaties, the invariable became totally assimilated by the non-flexible, as the variable became totally assimilated by flexible, the terms being used in free variation. However, there are some authors who analyses differently the concept of invariability, aspect which highlights the fact that the discussion has to be opened again in the most serious way, as in many flexible lexical-grammar classes of the Romanian language appear lexemes which are considered invariables, but which are not all also non-flexible.