Conjunctions are parts of speech that connect words, phrases, clauses, or sentences. There are three kinds of conjunctions: coordinating, paired, and subordinating.

For more information about conjunctions, also see these webpages:

• Compound Sentences,
• Varying Sentence Structure, and
• Comma Basics.

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:

• The authors agreed on the prevalence of the problem; however, they disagreed on the problem’s cause.
• Several employees complained about the new policies, and therefore, the manager held an all-staff meeting to address their concerns.

Paired conjunctions consist of two words or phrases that help make a point or establish alternatives. Although paired conjunctions can be helpful in structuring a sentence, they can also make sentences wordier than necessary, so use these conjunctions sparingly.

• both…and
  • The project will require significant investments of both time and money.
  • Both the students and the teachers were satisfied with the pilot program.
    • Note: When two subjects are connected by "both…and," use a plural verb (such as "are" or "were").
• not only…but also
  • Students who did not complete the assignment received not only a poor grade but also a warning from the teacher.
  • Not only did the student include full sentences from the source without using quotation marks, but he also failed to properly cite paraphrased material.
• either…or
  • Either the students were unprepared or the assessment was poorly written.
  • Participants in the survey could either choose from a list of possible answers or write in their own responses.
• neither…nor
  • Students who did not complete the project received neither praise nor rewards.
  • The staff neither followed the new policy nor asked for clarification.

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:

• after
• although
• as much as/as soon as/as long as
• as though
• because
• before
• how
• if
• in order to/in order that
• once
• since
• than
• that
• though
• unless
• until
• when/whenever
• where/wherever
• whether
• while

There are two ways to structure a sentence using a subordinating conjunction:

1. Main clause + subordinate clause
   • The teacher administered the test after giving instructions.
   • The author must avoid bias if she wants to maintain a scholarly tone.
   • I will turn in this assignment at midnight whether or not I complete it.
2. Subordinate clause + , + main clause
   • After giving instructions, the teacher administered the test.
   • If she wants to maintain a scholarly tone, the author must avoid bias.
   • Whether or not I complete this assignment, I will turn it in at midnight.

"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,

• Smith (2015) reported that more research was necessary.
  • Smith (2015) = subject
  • reported = verb
  • that more research was necessary = dependent clause, direct object of the verb "reported"
• The authors hypothesized that there would be significant results.
  • The authors = subject
  • hypothesized = verb
  • that there would be significant results = dependent clause, direct object of the verb "hypothesized"
• Jones (2014) asserted that confidentiality was maintained throughout the study.
  • Jones (2014) = subject
  • asserted = verb
  • that confidentiality was maintained throughout the study = dependent clause, direct object of the verb "asserted"
• Rephrasing these sentences into questions and answers is one way to see that the "that" clauses are acting as direct objects.
  • What did Smith (2015) report?
    • Answer: that more research was necessary
  • What did the authors hypothesize?
    • Answer: that there would be significant results
  • What did Jones (2014) assert?
    • Answer: that confidentiality was maintained throughout the study

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).

• For example, if readers see the sentence, "Smith (2015) reported more research was necessary (without 'that')," they may understand “more research” as the thing Smith reported and then have to backtrack and reread upon seeing “was necessary.”
• Any structure that leads to misinterpretation, even temporarily, can be an unwanted distraction from the writer’s message.
• In spoken English, however, "that" may be dropped in such sentences. (Intonation patterns—rising and falling pitch—give the listener clues that may not be present in writing.)

References

Caplan, N. (2012). Grammar choices for graduate and professional writers. University of Michigan Press.

Jamieson, P. (2012). Use of that. https://www.proofreadnow.com/blog/bid/89915/Use-of-That