求分析新概念三17课第一句：Verrazano,an Italian about whom little is known.

求分析新概念三17课第一句：Verrazano,an Italian about whom little is known.
Verrazano,an Italian about whom little is known,sailed into New York Harbour in 1524 and named it Angouleme.
关于这句话主要是an Italian about whom little is known,理解不清楚,首先我知道这句话是Verrazano的同位语,whom引导定语从句,
1：little的词性是什么,是名词?还是副词?
若little是名词,这句话就应该改成perter,an italian about whom little know,sailed into new york harbour.
若little是副词,这句话也应该改成perter,an italian about whom is little known,sailed into york harbour.
难道这是倒装句吗?又是怎么倒装的呀?
还是说little作为副词就应该放在be动词的前面?可我凭语感little就应该放在is的后面呀!
2：little如果是副词的话,whom在从句中到底做什么成分?whom指代的应该是an Italian,如果在从句中做主语的话,应该用who啊:an Italian who is little known,而这个about怎么解释,about后面一定会跟介词宾语,如果是about an italian的话,关系代词在从句中指代的应该是宾语,而about会提前到关系代词前面,那么也就是原句an Italian about whom little is known,不过这样的话,定语从句中主语是什么?
我是晕了,百思不得其解,搜了搜百度,虽然有相同的问题,但也没得到想到的答案.答得好会加分的.