是every has his own idea还是ideas ,这里用his对吗?还是应该用their

问题描述:

是every has his own idea还是ideas ,这里用his对吗?还是应该用their
关于符合不定代词还有什么特殊的~

应该是everynoe has his own ideas.
凡是前面有every everynoe 的后面都是三单形式.