In many languages, as shown cross-linguistically in Heine and Kuteva (2002), or for Chadic languages by Frajzyngier (1987), ventive verbs are the source of ventive markers in grammaticalization processes. Berber languages are, like Chadic ones, characterized by the extensive use of ventive verbal extensions, and to a lesser extent, andative ones. Contrary to what is generally assumed, and reflected in the label of the morpheme, ventive extensions in Berber are not limited to motion verbs, although those verbs (as 'arrive', wwḍ 'reach', ffγ, 'exit', ṛuḥ 'come/go') are part of the core group to which the extension is cliticized in all the Berber languages where this marker is grammaticalized, thus specifying the direction or endpoint of the movement. This group also contains other verbs that often, or usually bear the ventive clitic: fk 'give', awy 'carry', ğğ 'leave', ini 'say', af 'find'. We hypothesize that this group shows the first stage of grammaticalization of the ventive clitic. This core, common to a number of Berber languages, is further expanded in some of them, such as Kabyle (Northern Berber), so that a great number of verbal roots are associated to the ventive clitic: out of 10 000 verb occurrences in a continuous spoken corpus of Kabyle, 20% carry this clitic. Virtually any verb, mostly dynamic but also stative, can be associated to =dd, thus expressing such a variety of nuances as coming into existence, change-of-state, present relevance, focus, emphasis, and benefactive. ur=dd zwiğ-ɣ alamma t-kks=dd Fatima aɣrum g udəkkan NEG=VENT marry/NEGPFV-SBJ1SG until SBJ3SG.F-take/PFV=VENT Fatima bread:ABS LOC shelf:ANN 'I won't marry until Fatima is able to take the bread from the shelf' (Kabyle) The first aim of our study is to examine those uses and propose a grammaticalization network that may explain the variety of directions taken by this grammaticalization, which seems to follow the cline from propositional to interpersonal. Given the lack of ancient written sources, cross-linguistic comparison inside the language family is the only way in which the diffusion of that clitic into the system can be reconstructed. A likely candidate for the source of this grammaticalization is the verb ddu, which expresses motion (unspecified directionally), with a comitative component in Kabyle. That component can be the main feature of the verb in some Berber languages, such as Tahaggart (Southern Berber), whereas it is absent from others, such as Tachelhit (Northern Berber) (Galand 1978: 200). Another candidate is the deictic d, which comes into the composition of the 'future' (actually potential) particle ad, and is probably the source of the comitative preposition d, and the equative copula d. However, the tension distinction (d vs dd) being phonological in Berber, there is no direct equivalence between ventive clitic =dd and the deictic d. The second part of this study consists in providing arguments for both hypotheses, and suggesting that the grammaticalization process, rather than being traceable to one at the exclusion of the other, is the result of a complex network of semantic features shared by verb and deictic marker, as well as the result of analogical processes.