Commas, introductory - Graduate Writing Center

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Commas, Introductory


Introductory commas come between an initial word, phrase, or dependent clause and the main (independent) clause of a sentence. Their purpose is to signal the end of this introductory material and the arrival of the main subject and verb, helping readers to parse your syntax accurately on the first read.

To identify whether a sentence needs an introductory comma, locate the main subject—the one in the independent clause of your sentence—plus any modifiers appended to it. If any material precedes this main subject, insert a comma:

  • In the wake of the decisive naval engagement at Dan-no-ura, the victorious Minamoto clan established Japan’s first shogunate.

(In a sentence with multiple independent clauses, this comma will instead be a FANBOYS comma or a colon or semicolon.)

Note that a sentence can have more than one distinct introductory word, phrase, or clause; in such cases, place a comma after each.

Introductory Commas Practice Exercises

Which sentences need introductory commas? Where?

  1. If it is raining spaghetti will be served.
  2. Even if you have a dog a cat or a parrot is a nice addition to your menagerie.
  3. Whether the agreement will remain in effect will depend to a large extent on the testimonies next week.
  4. Import prices will likely continue to rise whether or not the agreement remains in effect.
  5. In 1815 however Napoleon abdicated following his defeat at the Battle of Waterloo.
  6. In 1815 however Napoleon had prepared for the encounter he was defeated by Wellington.

Answers

  1. If it is raining, spaghetti will be served. ("Spaghetti” is the main subject; without the comma, we might initially think it could rain spaghetti.)
     
  2. Even if you have a dog, a cat or a parrot is a nice addition to your menagerie. (“A cat or a parrot” is the main subject; with no comma, we might read the beginning as an unpunctuated list of three animals you might already have. Even with the intro comma, it could still sound like a list at first, which is a good argument for consistently employing the serial comma.)
     
  3. No intro comma needed: “Whether the agreement will remain in effect” is the main subject here, followed by the main verb, “will depend”; there is no introductory material before the main subject. Compare this sentence, in which the “whether” is part of an introductory dependent clause: “Whether or not the agreement remains in effect, import prices will likely to continue to rise.”
     
  4. No intro comma needed, as the independent clause comes first.
     
  5. In 1815, however, Napoleon abdicated following his defeat at the Battle of Waterloo. (“In 1815” and “however” are discrete introductory particles—one indicating time, one indicating tension or contradiction; each, therefore, gets its own introductory comma.)
     
  6. In 1815, however Napoleon had prepared for the encounter, he was defeated by Wellington. (“In 1815” still gets its introductory comma, but, this time, “however” introduces a long dependent clause; we don’t arrive at the main subject and verb until “he was defeated.”)
     

Further Practice and Other Introductory Comma Links

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Writing Topics A–Z


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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

adjectives, compound

advisor, selecting and working with

AI

apostrophes

appointment with GWC coaches, how to schedule

argument

article usage

artificial intelligence

assignments, understanding them

audience

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B

body paragraphs

booking an appointment with a GWC coach

brackets, square

brainstorming

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C

capitalization

citations

charts

ChatGPT

citation software

citation styles

clauses

clarity

clustering

coaching, about

coaching, how to schedule

colons

comma splices

commas, FANBOYS

commas, introductory

commas, list

commas, nonessential / nonrestrictive information

commas, Oxford

commas, serial

common knowledge

commonly confused words

compare-and-contrast papers

compound adjectives / modifiers

concision

conclusions

conference presentations

conjunctive adverbs

coordinating conjunctions

copyright and fair use

critical thinking

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D

dangling modifiers

dashes

dependent clauses

dependent marker words

display equations

distance learning

double submission of coursework

drafting

Dudley Knox Library

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E

editing your own work

editing: outside editors

em dash

en dash

equations

exclamation points

executive summary

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F

FANBOYS

FAQs

figures

first person, use of in academic writing

footnotes

fragments

free-writing

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G

generative artificial intelligence (AI)

gerunds

grammar

graphics

graphs

group writing

GWC appointment, how to schedule

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H

homophones

Honor Code, NPS

human subjects research

hyphens

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I

ibid.

incomplete sentences

independent clauses

Institutional Review Board

interviews, conducting

introductions

IRB

iThenticate

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J

Joining the Academic Conversation

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L

LaTeX

library liaisons

lists, syntax of

literature reviews

logic and analysis

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M

M dash

making a GWC appointment

mathematics

memos

methodology

modifiers, compound

modifiers, misplaced

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N

N dash

nominalizations

note-taking

noun clusters

numbers

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O

organization

outlining

Oxford comma

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P

paragraph development

parallelism

paraphrasing

parentheses

parts of speech

passive voice

periods

persuasion

phrases vs. clauses

plagiarism, how to avoid

plagiarism-detection software

plain language

polishing

prepositional phrases

prepositions

pronouns, clarity with

pronouns, grammar of

proofreading

publishing

punctuation

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Q

questionnaires, administering

questions

quotation marks

quoting

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R

Reading with Intent I

Reading with Intent II

redundancies

reference software

reflection papers

research

research guides, discipline-specific

research questions

restrictive vs. nonrestrictive information

reusing papers

reverse outlining

revision

roadmaps

run-on sentences

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S

scheduling a GWC appointment

self-citing

semicolons

sentence fragments

serial comma

signal phrases

significance

so what?

source blending

sources, engaging with / critiquing

sources, evaluating the reliability of

sources, citing

spelling

standard essay structure

STEM / technical writing

Strategic Reading I

Strategic Reading II

style

subject–verb agreement

subjects, grammatical

subordinating conjunctions

summarizing

surveys, administering

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T

tables

teams, writing in

technical writing

tense

that vs. which

thesis advisor, selecting and working with

thesis process overview

Thesis Processing Office (TPO)

thesis proposals: common elements

thesis statements

thesis writing

this, that, these, those

tone, professional

topic sentences

transitions

types of papers

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U

United States or U.S.?

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V

verbs and verb tense

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W

which vs. that

why write?

writer’s block

writing in groups / teams

writing process

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Z

Zotero

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