This is not he shirt.His is blue This is not his shirt.He is

This is not his shirt.His is blue.
说的意思是：这不是他的衬衫,“他的”是蓝色的.
He is blue.
说的意思是：他有点儿难过.blue 在英语中也可以做形容词“忧郁、难过”解.
如果句子的前半部都一样,"This is not his shirt" 你没故意拼错字的话,
两句话语法上都没错,后半句的解释不同罢了.
如果题目第一句就是 "This is not he shirt.His is Blue"
那么只有第二句才对!这不是他的衬衫,他有点儿难过.

his在这里是名词性物主代词，是可以代替his shirt的
所以要用This is not his shirt.His is blue

this is not his shirt

His is blue. This is not his shirt.这两句是对的。记住代词的用法就行了。