神马是Conjunctions？
被美称为glue words
Conjunctions 有哪些？
1.
Coordinating conjunctions or coordinators (and, but, or, nor, so, for, yet) connect ideas of equal structure or function. 并列连词
2.
Correlative conjunctions come in pairs and function like coordinating conjunctions to connectequal elements. 关联连词
The most common correlative conjunctions are
either . . . or,
neither . . . nor,
not only . . . but also,
whether . . . or,
both . . . and.
3. Subordinating conjunctions or subordinators such as if, when, where, because, although, since,whether, and while introduce a subordinate or dependent clause that is usually attached to anindependent clause and signal the relationship between the clauses. 从属连词（链接从句）
进一步的阅读资料
Coordinating conjunctions
http://www.chompchomp.com/terms/coordinatingconjunction.pdf
Subordinating conjunctions
http://www.chompchomp.com/terms/subordinateconjunction.pdf
练习worksheet
https://engwriting1.weebly.com/uploads/1/7/9/0/1790955/conjunctions.pdf
