Question

老师好，请教一句英语语法问题

Yet Davis inadvertently adds weight to such ascriptions by using the Puritans as the standard against which to assess the achievements and contributions of Southern colonials.
其中"which to assess the achievements and contributions of Southern colonials“我把它看成定语从句，但是在从句中没有谓语。

Answer 1

其中"against which to assess the achievements and contributions of Southern colonials“是带关系代词的不定式作定语 相当于一个定语从句
=against which he assesses the achievements and contributions of Southern colonials“
当定语从句的主语 与句子主语一致的情况下，可以用关系代词加不定式代替定语从句。

句子大概意思 Davis在不经意间用清教徒作为标准来对照评估南方殖民者所做的贡献及取得的成就来增加归属感的分量。

本问题归纳如下

该结构是“介词 +which +to do”，相当于一个定语从句。
具体说来，介词＋which/whom＋to do 结构可以改为：介词＋which/whom＋定语从句。
再如：
I don't have enough money with which to buy such an expensive dress.
＝I don't have enough money with which I can buy such an expensive dress.

Answer 2

要搞懂一个较复杂的句子中所包含的语法，首先要尝试把这个句子翻译出来；
你所说的这个句子大致意思是：Davis并非故意用清教徒作为标准来着重评估南方殖民者所做的贡献及取得的成就。

分析：其实这个句子没有你所说的定语从句，which只是做一个纯粹的代词而已，代指清教徒的标准，而against which to的意思可以翻译成用清教徒作为标准来......
请以后学习不要看到which就是定语从句，这样会误导你的，要根据这个句子的上下文来分析。

Answer 3

谓语是：assess

追问

assess是不定式，不能当谓语