Every part of linguistics has as object of study a certain component or a certain subsystem. The morphological-lexical component consists of the large variety of the units at the different range (word, basis, topic, morpheme) and different types of specified relations (syntagmatic, constitutive, paradigmatic), and it has as object of analysis the intern structure of the word being analyzed by delimitation, definition and classification of the given units, by description of the form where the given units are grouped in paradigms, by explanation of the manner how the integrated parts of the word are combined with each other forming its internal structure. In such language as Spanish, the difference between the word and morpheme is essential because the majority of existent and possible words are polymorphemic, and the polymorphemic word, as any other complex unity should be analyzed by means of the smaller units which integrate it, fact that we are going to investigate in the given article.