This pair of shoes fit perfectly. I will take this pair.
这个句子里，谓语是用的复数。但指示代词用的是单数，是否有误？

下面是一段摘自《美国传统词典[双解]》的关于“pair”的单复数解释（中英对照），看了就明白了：
Pair as a noun can be followed by a singular or plural verb. The singular is always used when pair denotes the set taken as a single entity: This pair of shoes is on sale. A plural verb is used when the members are considered as individuals: The pair are working more harmoniously now. After a number other than one pair itself can be either singular or plural, but the plural is now more common: She bought six pairs (or pair ) of stockings.
作为一个名词pair 后面可接单数动词或复数动词。 当pair 意味着把一套当成单个整看时，通常用单数形式： 这双鞋在打折 当把各组成部分当成单独的个体时， 用动词的复数形式：这对搭档现在合作得更加和谐 。 在一些而不是一个物体后，pair 本身既可是单数也可是复数， 但现在用复数更为普遍：她买了六双 （或 pair ) 裤袜