补足语简单来说就是补充说明主语或宾语的情况的,如(1) I saw him playing basketball yesterday.playing basketball 就是宾补,说明him这个宾语的动作状态 而在(2) He was seen playing basketball yesterday.playing basketball 就是主补,说明He这个主语的动作状态. 表语的概念汉语中是没有的,汉语中动词后面一般就是宾语了,而英语中联系动词,如be动词后面跟的类似宾语的成分则称之为表语,如 She is a beautiful girl.She is beautiful.a beautiful girl 和beautiful都属于表语 有问题欢迎单独交流