In Greek compounds, non-privative ἀ- is normally derived from copulative *sm̥ - (cf. Vedic sa-, sam-) or from *n̥-, allegedly the zero grade of the preposition ‘in’. In this paper, I propose that various such compounds contain traces of local particles. A reconstruction with ἀν- (the apocopated form of ἀνα-) is proposed for the nominal compounds Ἄτλας, ἀστεμφής, ἀσπερχές, while PIE *h2ed- (as in Latin ad, Gothic at) is recognized in ἄχρι, ἀσπάζομαι, ἀθρέω, ἀτενής, ἀσελγής, and ἀχανής. The remaining body of evidence for intensive and copulative alpha is also scrutinized. I argue that Greek preserves traces of *sm̥ - not only as a nominal prefix, but (like Indo-Iranian) also as a preverb. I see no compelling reason, however, to posit PIE *n̥- as the zero grade of ‘in’.