请问这句话的语法结构是否正确?

His obvious changes in character were brought out by a number of unfortunate incidents in life
生活中很多的不幸给他的性格带来了很明显的改变
这是个被动语句
主语 His obvious changes in character
谓语动词 were brought out
宾语 a number of unfortunate incidents in life
1.为什么一开头用his而不是he?
His obvious changes 这里是他的改变,而不是他改变,所以不能用HE
这个从HE 于HIS的单词意思就可以很好解决
2.本句的谓语动词是changes还是were brought out?为什么?
因为这是个被动语态：be+过去分词,所以这里were brought out是谓语动词,这是固定语法搭配,changes在这里不是动词而是名词改变的意思