The third V2 sentence type of Old English comprises four exceptional cases in which subject pronouns regularly invert with the tensed verb. These are: non-subject wh- questions, sentences introduced by `tha' and `thonne'[6] (when they are equivalent to modern English `then'), sentences with preposed negated or subjunctive verbs, and certain verb-initial sentence types (principally so-called ``Narrative Inversions''). Examples of these four cases are given in (6):
Under Pintzuk's analysis, the exceptionality in (6) arises because in these cases the verb moves further leftward than it does in ordinary declaratives, thereby passing the position of the clitic pronoun subject. Specifically, the verb moves to C-zero, perhaps because it must pick up certain morphosyntactic features there. Crucially, the structural position of the verb in wh- questions is not the same as in topicalized sentences, in contrast to the situation in CP-V2 languages, where the verb is always found in the higher functional projection. The split between questions and topicalizations helps to explain why, when English lost the V2 constraint, word order in questions was unaffected. Like Old English, the other IP-V2 languages also exhibit movement to C-zero in questions and certain other sentence types;[7] but these languages do not show the verb-third effect with pronominal clitics, because they do not have clitic pronouns that move to the CP/IP boundary.