be动词有三个分别是am is are 。I用am,you用are, is连用he she it,单数,第三人称单数用is,复数用are ,第三人称单数,不可数名词也用is 。例如:Iam you are he is she is it is we are they are Tom is my father is my mother is
am is的过去式是was. are的过去式是were
be动词有三个分别是am is are 。I用am,you用are, is连用he she it,单数,第三人称单数用is,复数用are ,第三人称单数,不可数名词也用is 。例如:Iam you are he is she is it is we are they are Tom is my father is my mother is
am is的过去式是was. are的过去式是were