Conjunctions are parts of speech that connect words, phrases, clauses, or sentences. There are three kinds of conjunctions: coordinating, paired, and subordinating.
Coordinating conjunctions connect words or phrases that serve the same grammatical purpose in a sentence. There are seven main coordinating conjunctions in English, which form the acronym FANBOYS:
F: for: The teachers were frustrated, for the school had cut funding for all enrichment programs.*
A: and: In this course, I will write a literature review, a case study, and a final paper.**
N: nor: The students did not complete their homework, nor did they pass the test.
B: but: The study is several years old but still valuable to this study.
O: or: At the end of the class, the students can choose to write an essay or take a test.
Y: yet: The patient complained of chronic pain, yet she refused treatment.
S: so: I have only been a nurse for one year, so I have little experience with paper charting.
* For is rarely used as a conjunction in modern English.
** When the conjunctions and and or connect three or more words or phrases, use a serial comma to separate items in the series.
Transitional words such as however and therefore can also function as conjunctions:
Paired conjunctions consist of two words or phrases that help make a point or establish alternatives. While paired conjunctions can be helpful in structuring a sentence, they can also make sentences wordier than necessary, so use these conjunctions sparingly.
Subordinating conjunctions join a subordinate clause to a main clause and establishes a relationship between the two. There are many subordinating clauses, but here are some of the most common:
There are two ways to structure a sentence using a subordinating conjunction:
That has a few different functions in English. This can lead to confusion because some instances of that are more optional than others in academic writing.
One important use of that is for embedding (inserting) a certain type of dependent clause called a noun clause into an independent clause. Frequently, such that-clauses serve as the direct object of a reporting verb (such as found, reported, posited, argued, claimed, maintained, and hypothesized) to introduce a paraphrase, summary, or quotation.
Key: Yellow, bold = subject; green, underline = verb; blue, italics = object
For example,
In formal written English, for clarity, most academic writers choose to keep that when it introduces a noun clause (Caplan, 2012). Leaving out that can cause the reader to misread (at first anyway) the subject of the dependent clause as being the object of the reporting verb (Jamieson, 2012).
References
Caplan, N. (2012). Grammar choices for graduate and professional writers. Ann Arbor, MI: University of Michigan Press.
Jamieson, P. (2012). Use of that. Retrieved from http://www.proofreadnow.com/blog/bid/89915/Use-of-That