看下这句话为什么没语法错误After1785,theproductionofchildren'sbooksintheUntiedStatesincreasedbutremainedlargelyreprintsofBritishbooks,oftenthosepublishedbyJohnNewbery,thefirstpublishertoproducebooksaimedprimar

Question

看下这句话为什么没语法错误
After 1785,the production of children's books in the Untied States increased but remained largely reprints of British books,often those published by John Newbery,the first publisher to produce books aimed primarily at diverting a child audience.
不需要解释啥意思,看的懂.为什么第一个逗号后面直接跟often,什么语法.first publisher 可以直接跟to produce不定式么,是我肯定用who引导.

Answer 1

often就是个副词,做频度状语
to produce这个不定式用来做the publisher的定语,此处因为用序数词修饰publisher,所以只能有不定式来修饰