This thesis is a study of the m and n elements, prefixed or suffixed to particles, verbs and nouns. The purpose is to examine how far a common origin can be a the various uses. Owing to the nature of the the earlier languages were relevant, and the seemed to mark a period which separates the secondary developments. Formally, the thesis consists of 3 parts (=7 chapters): First Part: M and N with Particles (i. e. with interjections (Ch. I), Prepositions (Ch. II), Adverbs (Ch. III) and Conjunctions (Ch. IV) ). Second Part : M and N with Verbs (i. e. Nif'al (Ch. V) and and N as . suffixes to Verbs (Ch. VI) ). Third Part : Ch. VII : M and N as Prefixes and suffixes to Nouns (including nominal forms of verbs). This classification is by the parts of speech to which the prefixes or suffixes are added. the character of the prefixes and suffixes as it results from the examination would establish a different order of treatment, which was not followed because that would have involved an anticipation of the argument. Thus ch. VI might come immediately after ch. I, for m and n as suffixes to verbs have been found to be of an interjectional character. Also ch. V might belong to the Third part, for Nif' al has been found to be rather a nominal form with prefix n-. The general result of this thesis is that m- and n- prefixes and suffixes all derive from an originally demonstrative use. This character has long been known., but isolated treatment of individual phenomena has led to views which required the general treatment provided in this study.