baina zer izan+zen
baina zer izan zen ?
b ai̯ ɲ a WORD_BOUNDARY s̪̻ e ɾ WORD_BOUNDARY i s̪̻ a n WORD_BOUNDARY s̪̻ e n WORD_BOUNDARY
b a i n a WORD_BOUNDARY z e r WORD_BOUNDARY i z a n WORD_BOUNDARY z e n WORD_BOUNDARY ? WORD_BOUNDARY