1.Do you think a five year old girl can care for her?
这里five-year-old作形容词,要有连字符
2.I told him that I was sure he could get it over.
这里要改成 get over it,不能把it放在两个词的中间
3.He said that he would go back home after clean the classroom.
改clean为cleaning,因为after是介词,后面要接动词的ing形式（动名词）请把那个背包递给吉尔,好吗?用英文翻译?是先could you 开头的