The aim of this paper is to give the semantic profile of the Greek verb-deriving suffixes -íz(o), -én(o), -év(o), -ón(o), -(i)áz(o), and -ín(o), with a special account of the ending -áo/-ó. The patterns presented are the result of an empirical analysis of data extracted from extended interviews conducted with 28 native Greek speakers in Athens, Greece in February 2009. In the first interview task the test persons were asked to force(=create) verbs by using the suffixes -ízo, -évo, -óno, -(i)ázo, and -íno and a variety of bases which conformed to the ontological distinctions made in Lieber (2004). In the second task the test persons were asked to evaluate three groups of forced verbs with a noun, an adjective, and an adverb, respectively, by using one (best/highly acceptable verb) to six (worst/unacceptable verb) points. In the third task nineteen established verb pairs with different suffixes and the ending -áo/-ó were presented. The test persons were asked to report whether there was some difference between them and what exactly this difference was. The differences reported were transformed into 16 alternations. In the fourth task 21 established verbs with different suffixes were presented. The test persons were asked to give the "opposite" or "near opposite" expression for each verb. The rationale behind this task was to arrive at the meaning of the suffixes through the semantics of the opposites. In the analysis Rochelle's Lieber's (2004) theoretical framework is used. The results of the analysis suggest (i) a sign-based treatment of affixes, (ii) a vertical preference structure in the semantic structure of the head suffixes which takes into account the semantic make-up of the bases, and (iii) the integration of socioexpressive meaning into verb structures.