During the process of enrichment of an au tomatic processing system in Mod ern Greek, we confronted the problem of ambigu ity between ad verbs and ad jectives with nominal use. The object of this stu d y is the retrieval of these ambiguities on the one hand , and the efforts to eliminate them on the other hand . We were based on the theoretical principles of Z. S. Harris as well as on the stu d ies of Mau rice Gross, who proposed the complete and systematic d escription of each language, aiming at the au tomatic text processing. In particu lar, the basis was a corpu s of 6.000 simple ad verbs and a corpu s of ~2.000 ad jectives with nominal u se. The verification of the analysis performed , was realised by UNITEX, an au tomatic processing system that was d eveloped in LADL (Laboratoire d 'Au tomatique et Documentaire Linguistiqu e) of the University of Marne-la-Vallee. During the research, we have come to the following conclusions: - There is ambiguity when an adjective with nominal use in neuter gender is found in the nominative, accusative and vocative of plural. For example: 1.0. / (daily/specially), adverb 1.1. / (everyday clothes/private lessons), adjective with nominal use (She is wearing her everyday clothes) (He offers private lessons) (He comes on a daily basis and meets me) (He is specially interested in literature) In order to resolve such ambiguities, there are the following solutions: - finite state automata, - creation of syntactical-semantic analysers, - classes of objects.