因为 They each 中的主语 they, each 只是主语的同位语。我们说主谓一致,指的就是谓语动词与主语一致,而不是与同位语一致。又如:
We each own a bicycle. 我们每人都有一辆自行车。
They each have a desk and a chair. 他们每人都有一张书桌、一把椅子。
They each have their own email address. 他们每个人都有自己的电子邮件地址。
We each 也一样,后面接复数动词。如:
We each have a notion of just what kind of person we’d like to be. 我们每人都有一个自己想成为什么样的人的想法。
但如果是 each of…作主语,则通常用单数谓语动词。如:
Each of us has a company car. 我们每人都有一辆公司的汽车。
Each of them has signed the petition. 他们每个人都在请愿书上签了名。
Each of the houses is slightly different. 每所房子都稍有区别。
Each of the boys was given an apple. 给了每个男孩一个苹果。