they are at home now 该句中的"now"是做状语用来修饰全句的吗??

如果now是状语的话,那么他用来修饰什么单词/句子成分???
但"状语"只能修饰"动词\形容词\副词"呀,而at home是"介词短语"????

what they are staring at?? They are laughing at me.他们正在笑话我. 帮忙翻译一句话they are not serious at that age To_the language barrrier,they are working hard at English. there are five people at my home,they are my parents and i 还是they are my parents and me things are different from the way they are at home;（人教版，初三，12单元）这里的they指什么 The boys are not doing a good job at all,are they? the boy are not doing a good job at all,are they? There are no lights on and no one answer the doorbell. They( ) be at home they are talking about the films (shown/showng) at the cinema. 为什么