这么说对吗?英语句子

问题描述:

这么说对吗?英语句子
Once I was a MA.major of American litarture,but now am intercultural communication.
尤其but now am intercultural communication.的
am对吗

去掉am.
问题是"I am a major of American literature."这种说法行吗?没见过.
应该是:Once I majored in American literature,but now intercultural communication.