词性意思:

adv. 本质上本来He was, essentially, a teacher, not a manager.

他本质上来说是个教师而不是经理。

The course is essentially theoretical in orientation.

该课程的目标基本上是理论性的。

The book is essentially a taster for those unfamiliar with the subject.

这本书基本上是让那些不熟悉该学科的人对其有个初步的了解。

The bulk of the text is essentially a review of these original documents.

正文的大部分基本上是对这些原始文献的回顾。