我用am，你用are，is用于他、她、它，单数用is，复数就用are。含be动词的陈述句变否定句在be后加not，变一般疑问句将be提前。一般疑问句的肯定回答：Yes,人称代词+be;否定回答：No,人称代词+be+not。如：They are teachers.----They are not teachers.----Are they teachers?----Yes,they are./No,they aren’t.
