B. Foundations of Language · Spelling, Grammar and Punctuation

Colons in Formal Letters and Memos

B3.3 A3.1About 40 minutes

Learning goals

I can use a colon after the greeting (salutation) in a formal letter.
I can use colons after the headings in a memo: TO:, FROM:, DATE:, SUBJECT:.
I can tell when a letter should use a comma or a colon after the greeting.
I can review other uses of the colon: lists, times and ratios.

Words to know

colon
A punctuation mark ( : ) that means here comes something.

salutation
The greeting at the start of a letter, like Dear Councillor Singh.

formal letter
A polite, serious letter to someone you don't know well, like a business, a mayor or a principal.

memo
Short for memorandum: a short, formal message sent inside a school, business or organization.

closing
The word or phrase before the signature, like Sincerely,.

Remember from Grade 5

In Grade 5 you used a colon to introduce a list after a complete sentence: Bring three things: a toque, mitts and boots. You also know the colon in times like 3:30 p.m.

In Grade 6 you'll use colons in two new places: the greeting of a formal letter and the headings of a memo.

Colons in formal letters

A formal letter is written to someone you don't know well, or for a serious purpose: asking your city councillor for a new crosswalk, inviting a guest speaker, or writing to a company.

In a formal letter, put a colon after the greeting: Dear Mayor Thompson:
In a friendly letter (to family or friends), use a comma: Dear Grandma,
If you don't know the person's name: To Whom It May Concern:
The closing still uses a comma: Sincerely, or Yours truly,

Use a title before the person's last name: Mr., Ms., Mrs., Dr., Councillor, Mayor, Chief.

Part of a formal letter	Example
Your address and the date	45 Maple Street, Thunder Bay, Ontario; October 14, 2026
Their name and address	Councillor Priya Singh, City Hall, ...
Salutation (with a colon)	Dear Councillor Singh:
Body	Paragraphs that explain your purpose politely and clearly
Closing (with a comma)	Sincerely,
Signature and printed name	Ava Martin

The parts of a formal letter (the names here are made up)

The layout of a formal letter (made-up names). The greeting gets a colon; the closing still gets a comma.

Colons in memos

A memo is a short formal message inside an organization, like a school or a business. It starts with headings, each followed by a colon:

TO: who it's for
FROM: who wrote it
DATE: when it was written
SUBJECT: what it's about (some memos use RE:, which means about)

Then comes the message, short and to the point. Memos don't need a greeting like Dear, or a closing like Sincerely.

The top of a memo. Each heading is followed by a colon. The message goes below the line.

Worked example

Let's write the start of a formal letter

Your class wants to invite a firefighter, Captain Diane Moreau, to talk about fire safety. Write the salutation and the first sentence.

This is a formal letter: you don't know her well, and it's for a serious purpose.
Use her title and last name: Captain Moreau.
Formal letters use a colon after the salutation: Dear Captain Moreau:
Start the body by stating your purpose politely.

Dear Captain Moreau:

Our Grade 6 class at Lakeview Public School would like to invite you to speak to us about fire safety.

Worked example

Let's fix a memo

Fix the punctuation: To all students / From, the principal / Date October 20 2026 / Subject. Pizza lunch

Each heading needs a colon, not a comma or period.
The date needs a comma between the day and the year: October 20, 2026.
Headings are often in capitals so they stand out.

TO: All students FROM: The principal DATE: October 20, 2026 SUBJECT: Pizza lunch

Other colon jobs (review)

Lists after a complete sentence: We need three tools: a shovel, a rake and a hoe.
Times: The bus leaves at 8:15 a.m.
Ratios in math: the ratio of red to blue marbles is 3:2.
Script dialogue: MAYA: Where's my toque? (You'll learn this in another lesson!)

Just for fun

Riddle: What has two dots, works in letters, memos, scripts and clocks, and never takes a day off?

The colon! (Even at 12:00 midnight.)

Hands-on activity

Write a real formal letter

You need: paper and a pencil, or a computer, and an envelope (optional).

Think of a real reason to write a formal letter: thanking a community helper (a crossing guard, a librarian, a coach), asking a local business to donate to a school event, or suggesting an idea to your school principal.
Plan it with the parts from the chart: your address and date, their name and address, salutation, body, closing, signature.
Write the salutation with a colon, and the closing with a comma.
Write 2 or 3 short, polite paragraphs: who you are, why you're writing, and what you hope for.
Now write a memo to your family about a family event (a games night, a cleanup day). Use TO:, FROM:, DATE: and SUBJECT:.
With a grown-up's help and permission, send your letter by mail or email.

Your turn

Add the right punctuation to this formal salutation: Dear Dr. Okafor

Add the right punctuation to this friendly salutation: Dear Uncle Ray

What are the four common headings at the top of a memo?

What punctuation follows the closing Sincerely?

Formal or friendly? A letter to a bank asking about a savings account for kids.

Write a salutation for a letter when you don't know the person's name.

Add a colon: The concert starts at 7 30 p.m.

More practice: warm-up

What does a colon mean, in a few words?

Comma or colon? Dear Grandpa___

Comma or colon? Dear Mayor Tremblay___

What does RE: mean in a memo?

Add a colon: The ratio of girls to boys is 4 3.

More practice: on your own

Fix: Dear Ms. Chen, I am writing to ask about volunteering at the food bank. Sincerely: Leo

Write the four memo headings for a memo from the Eco Club to all classes, sent on November 16, 2026, about a litter-free lunch day.

Why doesn't a memo need Dear or Sincerely?

Is the colon correct? My favourite sports are: hockey, soccer and lacrosse.

Formal or friendly? Explain: an email to your cousin about the weekend.

Challenge

Write the salutation and opening sentence of a formal letter to the chief of a nearby First Nation, Chief Margaret Hill (a made-up name), inviting her to your school's Treaties Recognition Week assembly.

Find and fix all the punctuation errors in this memo heading: TO, Grade 6 parents / FROM Ms. Ali / DATE; December 1 2026 / SUBJECT Winter concert

Explain three different jobs a colon can do. Give an example of each.

Check your understanding

Quiz

Which salutation is correct for a formal letter?

Which salutation is correct for a friendly letter?

Which memo heading is punctuated correctly?

Which closing is correct?

What is a memo?

Where does a colon belong?

For parents and teachers

Big idea (B3.3): The Grade 6 curriculum names the use of colons in formal letters and memo salutations as a Grade 6 punctuation skill. Writing real letters connects language to community life (A3.1).

How to help at home:

Show your child real formal letters or emails (from a school, a bank, a business) and point out the colon or comma after the greeting.
Help your child write and send a real thank-you letter or a polite request.
Use memo format for family notices on the fridge.

Common difficulties:

Using a colon in friendly letters. Ask: "Do you know this person well?"
Putting a colon after the closing. The closing always gets a comma.
Colons after incomplete sentences (My pets are:). Review the Grade 5 rule: a complete sentence comes before a list colon.
Note: many Canadian business emails use a comma after the greeting too. The colon is the more formal choice and is what your child is learning at school.