Which is the proper punctuation--a colon or a semicolon--for connecting related thoughts within a sentence?

The use of a semicolon is restricted to complete thoughts that could otherwise stand alone as separate sentences:

An action is based on tacit knowledge; this knowledge may

not always be put into words. 
Each expert fails to see the "whole world"; they see only the

part they specialize in. 
Group members must be able to receive accurate feedback on

their achievements; individual accountability is an important

aspect of cooperative learning. 

Each of the above examples could have been separated into two sentences by using a period; however, a closer relationship between thoughts is created by using the semicolon.

A colon or dash may also be used to connect complete thoughts; however, they differ from the semicolon in the degree of emphasis they give to each thought. While a semicolon emphasizes both thoughts equally, a colon emphasizes the second thought and a dash emphasizes the break in the sentence (and can also emphasize the first thought):

This procedure is called coercive because no provision exists

for mutual exchange: communication begins with the belief

that the chairperson's position is correct. 
Trust is a necessary condition for cooperation and

communication: as trust increases, cooperation stabilizes

and communication improves. 
Socializers are intuitive and come up with assorted ideas--some may even be practical.
Relaters focus on building trust and long-standing

relationships -- they like steadiness. 

If one of the thoughts to be linked is incomplete, i.e., unable to stand alone as a sentence, either a colon or dash must be used (again depending upon the degree of emphasis desired):

Your most familiar style is your core behavioral type:

a unique personality style most evident when you simply

"act yourself." 
Self-contained individuals prefer to be more reserved--

choosing to maintain their distance.

When may words like however, further, and therefore, be used with a semicolon?

Transitional words and phrases like thus, therefore, for example, on the other hand, nevertheless, further, indeed, and however, may be used with semicolons to clarify the relationship between the thoughts:

You can choose to be adaptable or not adaptable; moreover,

you can even elect the days you want to be adaptable. 
People do not want to change; however, when things start to

go wrong, they begin to explore alternative behaviors. 

Simpler conjunctions like and, yet, but, so, or, for, and nor are not used with semicolons.

What is the correct punctuation after the salutation of a letter--a colon, semicolon, or comma?

Either a colon or a comma may be used, depending upon the degree of formality desired.

A colon follows the salutation in formal letters:

Dear Ms. Gregorson:

Members of the Board:

A comma follows the salutation in informal letters:

Dear John,


The use of a semicolon after a salutation is improper.

In what other instances are colons used?

Colons may introduce lists or examples:

Several factors can adversely impact message transmission: 
  • Lack of preparation
  • Lack of organization
  • Lack of vocal variation
Visuals ought to be: (1) professional, (2) communicative,

(3) flexible, and (4) interactive. 
Many questions are usually asked: "What time is it?" "When

will we get home?" "Are we there yet?" 

Colons separate titles from subtitles:

Group Dynamics: Experiential Learning

Decision Making: Decision by Consensus

Colons separate hours from minutes, volumes from pages, and the first part of a ratio from the second:

4:45 p.m.

See Psychology Today 3:133-134.

The ratio is 1:3.65.

Must a comma always be inserted between two complete thoughts within a sentence?

No, the comma may be omitted if both complete thoughts are short:

We looked around and we saw no damage. 

However, as the complete thoughts become longer and more complex, a comma is placed before the coordinating conjunction (and, but, or, for, nor, so, yet) to separate the thoughts and facilitate understanding:

The effectiveness of a decision depends upon logical

soundness, and each team member must assume

responsibility for contributing to the discussion

of the possible alternatives. 
We could arrange for lunch to be brought in at noon,

but it might be very difficult to predict exactly

when the speaker will finish her lecture. 

A comma is not used with connecting words like therefore, however, consequently, and so on. Instead, a semicolon is used.

Is a comma optional before the conjunction that occurs in a series of three or more words, phrases, or clauses?

No. Formerly, this comma was considered optional, but the current trend is to make its use mandatory to reduce the possibility of misinterpretation:

Lunch included soup, salad, bread and butter, and dessert. 
We'll fly to Wentworth, register at the Plaza Hotel, and take

a guided tour of the plant before retiring for the evening. 

When all the items in the series are linked by conjunctions, no commas are used:

The weather was sunny and warm and quite pleasant. 

If any item in the series contains a comma, a semicolon is used to separate series items:

We left the stadium; picked up John, Mary, and Bill; and

attended a movie, which turned out to be quite boring. 

Are commas used to separate two or more adjectives that precede a noun?

Yes, providing the adjectives equally modify the noun. If one adjective modifies another adjective instead of the noun, no comma is used between those adjectives:

The old, tattered flag hung limply from the pole. 
The rich, dark red hues were quite attractive.

Must a comma always separate an introductory phrase from the main body of the sentence?

Whether a comma should be used to separate an introductory phrase from the main body of a sentence depends upon the length of the introductory thought:

When caught in a gray area with no clear-cut guidelines, they

usually ask for permission before taking action. 
In that instance you must always respond quickly. 

In general, a comma between an introductory phrase and the main body of a sentence should help to clarify and reduce confusion. If the introductory phrase is short and leaves virtually no possibility for any misunderstanding, the comma should be eliminated.

Should commas be used to separate phrases and clauses that are located within the body of the sentence?

Not necessarily--use of a comma depends upon whether the inclusion of the phrase or clause is essential to the understanding of the sentence. If the phrase or clause is essential, commas are unnecessary; but if the phrase or clause is nonessential, commas are required:

Essential: Our success depends on your ability to find

solutions that will save us money. 
Nonessential: The results of the study, which were reprinted

in the newsletter, supported the managerial decision. 

What are some other ways that commas may be used?

Commas separate titles and degrees from names:

Our representative is Fred Simpson, CEO of Altron Avionics.

Robert Novay, EdD, will conduct the workshop. 

Commas separate items in addresses and in dates where the month and day precede the year:

Send your reply to KCI, 101 Day Drive, Midvale, Indiana.

The meeting was held May 24, 2005, long before the deadline.
The meeting was held in May 2005.

The meeting was held 24 May 2005.

Commas set off transitional words like however, thus, further, for instance, etc., when they introduce sentences or link two complete thoughts:

Further, the reply that we received was unsatisfactory.

The shipment was damaged; however, we agreed to accept it.

Are numbers and letters that designate items in a displayed list followed by a period?

Yes. Periods are placed after numbers or letters that define items in a displayed list:

  1. Resilience
  2. Vision
  3. Competence
  1. Core behaviors
  2. Alternative behaviors
  3. Adaptive behaviors

Are periods placed at the end of items in a displayed list?

Periods are placed after items in a displayed list when one or more of the items is a complete sentence or when the listed items complete the sentence begun by the introductory phrase.

In general: 
  1. Extend your comfort zone.
  2. Accept necessary changes.
  3. Say "No" occasionally.
The communicative technique of anticipation includes:
  1. Establishing rapport and understanding.
  2. Gaining respect.
  3. Overcoming stereotypes.
Anticipation includes three skills:
  1. Establishing rapport and understanding
  2. Gaining respect
  3. Overcoming stereotypes

Are periods placed at the end of headings?

A period is placed at the end of a run-in heading but not after a displayed heading--unless it is written as a complete sentance:

Self-interest. People are often motivated to act and cooperate

on the basis of how well their goals are being furthered. 
People are often motivated to act and cooperate on the basis

of how well their goals are being furthered. 

Are all abbreviations followed by a period?

Periods follow some abbreviations, but the trend is to eliminate periods in and after abbreviations. However, periods always follow abbreviations that spell normal words. See ABBREVIATIONS.

When a courteous request is stated in the form of a question, is a question mark used?

No. A period follows a courteous request that is stated as a question:

Will everyone please take their seats.
Will you please send me two copies of the final report. 

What punctuation follows a direct statement that is meant to be a question--a period or a question mark?

A question mark follows a statement that is written as a declaration but intended as a question:

That's your final word? 
You weren't able to secure any other responses to the survey? 

What end punctuation is used with a sentence that contains an embedded question?

A question mark is used when a declarative sentence contains a question:

We're required, aren't we, to respond promptly to their

demands for proof? 

What is the correct punctuation when expressing doubt about the accuracy of a stated element?

Doubt is expressed by placing the question mark within parentheses:

The conference was held in April 1974 (?) at the Vatican. 
The conference was held at the Vatican in April 1974 (?). 

Should quotation marks be used with indirect quotations?

No. Quotation marks enclose direct quotations but are not used with indirect quotations:

The invitation says, "You're invited to attend the reception." 
The invitation says that you're invited to attend the reception.

How are long quotations punctuated?

Long quotations may be enclosed by quotation marks, or they may be indented from both left and right margins (without quotation marks).

When quotation marks are used with quotations that extend for more than one paragraph, quotation marks should appear at the beginning of each new paragraph within the quotation.

How is a quotation within a quotation punctuated?

Single quotation marks are used to define a quotation within a quotation:

The report stated, "All territories have the 'right of eminent

domain' clause included in their charters." 

When a quotation has some form of end punctuation (period, comma, question mark, etc.), where is that end punctuation placed--inside or outside the quotation marks?

The answer depends on the type of end punctuation that is used.

Periods and commas are always placed inside the closing quotation marks, giving a cleaner appearance to the printed page:

The manuscript was entitled "Insect Life Cycles and

All trade organizations are expected to follow "Gatlin's Rules

for Limited Engagements." 

Semicolons and colons are always placed outside the closing quotation marks:

The original report was filed under "Corporate Holdings";

the final report was filed under "Acquisitions‚Historical." 
Please attach the following items to your "Expense

Summary & Voucher": 
  1. Airline ticket
  2. Car rental contract
  3. Hotel/Motel receipt

Question marks that are part of the quotation are placed inside of the quotation marks:

She asked, "Is there a doctor in the house?"

Question marks that are not a part of the quotation are placed outside of the quotation marks:

Where is the section entitled "Insect Life Cycles"? 

What are other ways that quotation marks may be used?

Quotation marks indicate titles of articles, sections, volumes, and other parts of longer documents:

The text "Joining Together: Group Theory and Counseling

Skills" was written by David and Frank Johnson. 
The chapter entitled "Tension Within Groups" was

particularly fascinating. 
The article was lifted from Volume II of "The History of

Medieval Land Practices." 

Quotation marks can define words that are used in a special or abnormal sense:

Your listing of so-called "facts" is hard to believe. 
How are "shorts" and "longs" delineated in the final totals?