表语就是能与系动词一起构成谓语的成分.可以是形容词,动词不定式,也可以是从句.系动词则分三大类：be动词,感官动词（smell,look,taste,feel,sound etc.）,和“变得...”意的动词如get,become,turn,go 等.
例句：He is a student.
His face turned red.
The cake looks dilicious.
这三句中student,red 和dilicious 就是表语.
还有,My wish is to be a doctor.
My suggestion is that you shoul go now.
这两句中,第一句,to be doctor 是表语,第二句,that 从句是表语.
宾语补足语则是对宾语的补充说明,例如：
What you said made him angry.
angry 就是个宾补,它补充说明宾语him的状态.