This preliminary chapter provides a general characterization of verbs by discussing a number of salient semantic, morphological and syntactic properties of verbs, to the extent that these are relevant to their syntactic behavior. Important works used in this chapter are De Haas & Trommelen (1993), Haeseryn et al. (1997), Klooster (2001), and Booij (2002/2015a). Section 1.2 presents a number of semantic and syntactic classifications and aims to provide a classification combining basic insights from both perspectives. Since we have not been able to do justice to the vast theoretical literature on the syntactic and semantic classification of verbs and the relationship between them, we refer the reader to the surveys of these topics in Van Hout (1996: §1) and Levin & Rappaport Hovav (2005). References to the more specifically semantic proposals discussed in this chapter are given in the main text: the most important are Vendler (1957), Verkuyl (1972/1993), Dowty (1979), Van Voorst (1988), and Tenny (1994). The syntactic classification includes the unaccusativity hypothesis, which was first formulated in Pollmann (1975: §5.4) and Perlmutter (1978) and has become increasingly important since Hoekstra (1984a: §3.3) and Burzio (1986). The classification finally adopted in this chapter is discussed in more detail in Chapter 2, where the reader is supplied with further references. The discussion of inflection in Section 1.3 is indebted to Haeseryn (1997), Klooster (2001: Appendix), Booij (2002/2015a), Van der Wouden (2015a), where the reader will find much more detail than given here. The main references for Section 1.4 can be found in the main text; the introduction to imperative constructions in Van der Wurff (2007) is recommended for further study. The discussion of tense theory and its interaction with mood/modality and aspect in Section 1.5 is based on Verkuyl (2008), Verkuyl & Broekhuis (2013) and Broekhuis & Verkuyl (2014) and has benefited greatly from Comrie (1985), Hornstein (1990) and Palmer (2001). For further study, we refer to the collection of papers on tense and aspect collected in Binnick (2012) and Verkuyl (2022).