Commas, list, including Oxford - Graduate Writing Center

Nested Applications
GWC - list including oxford

Commas, List, Including Oxford


A list consists of three or more grouped items: “bread and cheese” is a grocery list but not a grammatical list; “bread, cheese, and pickles” is both.

When constructing a list, place a comma between each item:

Variables analyzed in the regression included population size, GDP, third-party assistance, and number of previous endogenous conflicts.

That last comma—the one before the “and” (or “or”) that precedes the last item in a list—is known as the “Oxford” or “serial” comma. Ironically, perhaps, the Oxford comma is less frequently used in British English than American, and it is technically optional, provided you’re consistent within a given document.

 

Better safe than sorry

That said, leaving out the Oxford comma can potentially generate confusion (and chuckles) in your reader. Take, for example, this sentence:

This thesis is dedicated to my parents, Professor Chakrabarty and Professor Moustakas.

Did your parents advise your thesis?

The slip in meaning arises here because the comma is overworked: we could read this sentence either as a list with no serial comma or as apposition—a construction in which something is renamed. Compare this version, which clears things up:

This thesis is dedicated to my parents, Professor Chakrabarty, and Professor Moustakas.

Now it’s certain that we’re looking at a list.

Always including the Oxford comma is a useful way to minimize ambiguous list constructions and reserve that precious brainpower for other writing-related conundrums.

 

But wait

The Oxford comma is not a silver bullet for preventing ambiguity, however:

This thesis is dedicated to my kids, Sylvia, Hart, and Ezra, as well as my parents.

Are Sylvia, Hart, and Ezra the children here, or are they some other people this author wanted to thank? Again, are we looking at an appositive or a list?

In cases like this one, it can be useful to supplement commas with dashes or semicolons or other structural markers, which can clarify the boundaries between list items:

  • This thesis is dedicated to my kids—Sylvia, Hart, and Ezra—as well as my parents.
  • This thesis is dedicated to my kids; to Sylvia, Hart, and Ezra; and to my parents.

Finally, consider simply rearranging the list items:

I went on a walk with my dog, Lewis, and his sister.

Unless you’re packing multiple leashes and plenty of doggy bags, we’ll probably want this version:

I went on a walk with Lewis, his sister, and my dog.

 

Lists vs. Nested Pairs

One particularly common comma error is treating a nested pair as a list:

Chapter I explains the research problem, methods, and discusses relevant literature.

This sentence is not a list; rather, it contains a pair of verbs (explains and discusses), one of which distributes to a pair of direct objects (research problem and methods). These pairs should each be treated in the usual way—connected with “and,” with no commas:

Chapter I explains the research problem and methods and discusses relevant literature.

In constructions like this one, writers might be tempted to retain the comma before the second "and": "explains the research problem and methods, and discusses relevant literature." But, for the same reason, this comma, too, is unnecessary.

 

Conclusion

As with any other construction, achieving clarity in your lists requires being attuned to possible misreadings and quashing them with punctuation, restructuring, and the rest of your syntactic toolkit.

 

List Commas Links

GWC - all topics list heading

All-Topics Index


The following index makes searching for a specific topic easier and links to the appropriate place in the sequenced material. We think we have most of them, but please email us at writingcenter@nps.edu if we are missing something!

A-Z content menu

A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q R  S  T  U  V  W  X  Y  Z

A

abbreviations

abstracts

academic writing

acronyms

active voice

advisor, selecting and working with

apostrophes

appointment with GWC coaches, how to schedule

argument

article usage

assignments, understanding them

audience

return to top 

B

body paragraphs

brackets, square

brainstorming

building better sentences tips

return to top 

C

capitalization

citations

citation software

citation styles

clauses

clarity

clustering

coaching, about

coaching, how to schedule

colons

comma splices

commas, FANBOYS

commas, introductory

commas, list

commas, nonessential elements

commas, Oxford

commonly confused words 

compare-and-contrast papers 

concision

conclusions

conjunctive adverbs

coordinating conjunctions

copyright and fair use

critical thinking  

return to top 

D

dangling modifiers

dashes

dependent clauses

dependent marker words

display equations

double submission of coursework

drafting

return to top 

E

editing your own work

editing: outside editors

exclamation points

executive summary

return to top 

F

FANBOYS

FAQs

first person, use of in academic writing

footnotes

fragments

free-writing

return to top 

G

gerunds

grammar

group writing

GWC appointment, how to schedule

return to top 

H

homophones

hyphens

return to top 

I

ibid.

incomplete sentences

independent clauses

introductions

return to top 

J

Joining the Academic Conversation

return to top 

L

LaTeX

library liaisons

lists, syntax of

literature reviews 

logic and analysis 

return to top 

M

making a GWC appointment

mathematics

memos

methodologies

misplaced modifiers

return to top 

N

nominalizations

note-taking

noun clusters

numbers

return to top 

O

organization

outlining

Oxford comma

return to top 

P

paragraph development 

parallelism

paraphrasing

parentheses

parts of speech

passive voice

periods

persuasion

phrases vs. clauses

plagiarism, how to avoid through citations

plain language

polishing

prepositional phrases 

prepositions

pronouns

publishing

punctuation

purpose of research

return to top 

Q

questions

quotation marks 

quoting

return to top 

R

reading with intent

redundancies                                                                

reference software

reflection papers 

research

research questions

reusing papers

reverse outlining

revision

roadmaps                                            

run-on sentences 

return to top 

S

scheduling a GWC appointment

self-citing

semicolons

sentence fragments

serial comma

signal phrases

significance

so what?

sources, engaging with / critiquing

sources, evaluating the reliability of

sources, citing

spelling

standard essay structure

STEM / technical writing 

style

subject–verb agreement

subjects, grammatical

subordinating conjunctions

summarizing

return to top 

T

technical writing

that vs. which

thesis writing

thesis advisor, selecting and working with

thesis process overview

thesis process tips

thesis proposals – common elements                                                     

thesis statements

this, that, these, those

tone, professional

topic sentences 

transitions

types of papers

return to top 

U

United States or U.S.?

return to top 

V

verbs and verb tense

return to top 

W

which vs. that

Why write?

writer’s block 

writing process

return to top 

Z

Zotero

return to top