还 没 还 没
hai2 mei2 hai2 mei2
adv adv adv adv
还 没 还 没 !
x ai̯˧˥ WORD_BOUNDARY m ei̯˧˥ WORD_BOUNDARY x ai̯˧˥ WORD_BOUNDARY m ei̯˧˥ WORD_BOUNDARY 
还 WORD_BOUNDARY 没 WORD_BOUNDARY 还 WORD_BOUNDARY 没 WORD_BOUNDARY