however用在句首?

问题描述:

however用在句首?
“Another point I noted from my observation of the student corpus is that with 1 or 2 exceptions,* students only ever use However,at the beginning of a sentence.
In contrast,the native speaker corpus reflected a much more flexible approach - one point of particular interest to me is that in most cases when However is used to begin a sentence,that sentence just happens to be the first sentence of a new paragraph.”

句首,不作为从句的引导词的话,应该都是“尽管如此”的意思吧.
作为引导词则应该是:无论如何(高,好.)都,的意思吧