In this paper, I discuss verb second (V2) and clitic second languages (CL2) as an object of the parametric typology. V2 systems are a small group of languages sharing a number of parameters constraining the clausal architecture and the finite verb placement. CL2 systems are a large group of languages sharing a number of parameters constraining the clausal architecture and clitic ordering. The constituting property of both V2 and CL2 syntax is the bottleneck condition licensing only one constituent in XP. The ordering of finite verbs in V2 languages and the ordering of clitics/clitic clusters in CL2 languages is explained as head movement of the diagnostic category (verb or clitic) to 2P accompanied by the XP-movement of phrasal categories. An extension of the class of rigid V2 languages is the class of V1/V2 languages which license IS-motivated V1 orders in declarative clauses, while CL1/CL2 languages are rare.