This paper presents a comparison between to-bearing relative clauses, adverbials and interrogatives on the one hand, vs. their to-less variants on the other, and discusses the functions associated with the presence of to. It is argued that at least three different instances of to should be distinguished. One converts relative clauses into appositive ones, which are necessarily semantically connected to the matrix clause and it makes the semantic connection override even apparent lack of appropriate syntactic connection. It attaches to relativizers, including gdzie ‘where’ and kiedy ‘when’ relative clauses. It is argued that the same segment is present in adverbials, triggering a factitive presupposition, as is the case of appositive relatives generally. The second to links the content of a kind relative, an adverbial or a wh-interrogative to previous contexts, possibly triggering a pragmatic presupposition. The third converts standard wh-interrogatives into either rhetorical or thetic questions. It is argued that while in the third instance we are dealing with a separate word and in the second with a clitic, the first to, hitherto unidentified or possibly falsely identified in relevant literature, appears to have both some characteristics of a clitic and of an affix.