||Old British pi, pe can be connected with OIr. cía, ce, ci e.g. cía chruth 'what way?'. It is however not identical with Welsh pa, which may reflect an old oblique case form or an adverb used as an oblique case form. It is tempting to compare pa with Oir. co- 'how'? and reconstruct an adverbial interrogative stem *kʷa-. Late Proto-British *pa was lost in South-West-British and survived only in Welsh, where it was confused with *pɨ > OW pi, MW py.