the girl isn't （ ）（dance)这里的dangce要用ing形式吗

the girl isn't （ ）（dance)这里的dangce要用ing形式吗 dance的ing形式 Paying over the Internet isn't always safe.这句话Pay为什么变成ing形式? isn't的复数形式 The girl (dance)beautfully用所给单词的适当形式填空 stories原形,sun的形容词,dance英译中,see（ing形式）一周一次（中译英） 用单词的适当形式填空：I think the bus ride isn’t ____.（bore） the girl likes ------------- [dance] v-ing形式的用法-Henry doesn't seem like the same person.-（ ）so mu 英语ing形式,pass me the cloth,I want to clean the windows.这里的pas The leather was found clinging to the tree.请问这里的ing形式是什么语法现象 no it isn't 的复数形式