单数。either of的意思是：pron.任何一个。例句：You may take either of the roads.两条路你随便走哪一条。either of 表示“两者之一”，其后谓语动词用单数。
either of例句
Does either of the parties want to stop the fighting?
双方中没有一方想停止战斗吗？
She drove away before either of them could speak again
没等他俩中任何一人再开口，她就驾车而去。
Do either of you smoke cigarettes or drink alcohol?
你们俩有人吸烟或喝酒吗？
Mary was a better rider than either of them and she excelled at outdoor sports
玛丽的骑术比他们俩都要好，而且她擅长户外运动。
In Britain, we have so far escaped, in large measure, either of these afflictions.
在英国，我们迄今为止已经远远地避开了这两类麻烦。