From Icelandic Parsed Historical Corpus (IcePaHC)
WPP like English whereto. hvaðan is tagged WADV and af as P.
( (IP-MAT (NP-SBJ (NPR-N Sakarías-sakarías)) (VBDI svaraði-svara) (NP-OB2 (N-D engl$-engill) (D-D $inum-hinn)) (, :-:) (" "-") (CP-QUE-SPE (WPP (WADVP (WADV hvaðan-hvaðan)) (P af-af)) (IP-SUB-SPE (PP *T*-1) (MDPI skal-skulu) (NP-SBJ (PRO-N eg-ég)) (NP-OB1 (D-A þetta-þessi)) (VB vita-vita))) (. ?-?)))
HVAÐAN AÐ is parsed the same, hvaðan as WADV and að as P and then the whole phrase as WPP.