key note (keynote)

Writers often mix keynote (one word) and key note (two words). Use keynote for the main speech or theme and as a verb meaning "to deliver that address." Use key note when key modifies note-that is, an important annotation, comment, or a musical pitch.

If you just need a quick fix, scan the short tests below and copy a ready-made rewrite.

Quick answer

Use keynote (one word) for the principal speech, the main theme, or the act of delivering that speech. Use key note (two words) when you mean an important note or comment-key modifies note.

keynote (one word): the keynote speaker, the keynote address, to keynote (verb).
key note (two words): a key note in the margin, a key note about sources, a key note (musical pitch).
Avoid key-note (hyphen) unless a house style or a rare compound-modifier needs it; usually rewrite instead.

Core explanation: what each form means and when to use it

Keynote as one word names the dominant theme or the main speech at an event. It also works as a verb: to keynote means to deliver that main address. Key note as two words treats key as an adjective that describes a note-an important comment, a margin remark, or a musical pitch.

To choose the right form, ask two quick questions: 1) Is this talking about a speech or theme? If yes, use keynote. 2) Is this talking about an important annotation or a short remark? If yes, use key note.

Spacing and hyphenation notes

Modern usage prefers one word for the speech/theme and two words when key modifies note. Hyphenation (key-note) is uncommon and can look dated; follow a specific style guide only if required.

If you write about a speaker or address, close it: keynote speaker, give the keynote.
If you mean an important note in a document or margin, keep it open: a key note about sources.
Reserve key-note only for rare cases where a hyphen makes a compound modifier clearer.

Real usage - work, school, and casual examples

Seeing each form in context helps you spot the right choice quickly. Below are short examples grouped by setting.

Work: The CEO will keynote the annual summit.
Work: The conference's keynote focused on our growth strategy.
Work: Add a key note about budget changes to the slide notes.
School: The professor asked her to deliver the keynote at graduation.
School: The essay's keynote is the role of small businesses in recovery.
School: Leave a key note about bibliography style at the end of your draft.
Casual: He keynoted his friends' reunion with a short toast.
Casual: The party's keynote was her homemade cake.
Casual: I left a key note on the fridge about milk.

Wrong vs right examples you can copy

These pairs show common slips and their corrections.

Wrong: The key note speaker arrived late.
Right: The keynote speaker arrived late.
Wrong: Please key note the opening remarks.
Right: Please keynote the opening remarks.
Wrong: Add a keynote about sources at the end of the paper.
Right: Add a key note about sources at the end of the paper.
Wrong: The key-note of his argument was clarity.
Right: The keynote of his argument was clarity.
Wrong: She left a keynote in the margin.
Right: She left a key note in the margin.
Wrong: Will you keynote me a note after lunch?
Right: Will you leave a key note for me after lunch?

How to fix your own sentence

Fix the whole sentence, not just the phrase. Replace the form, then read for tone and flow. If the sentence still sounds awkward, rewrite instead of forcing one word into the wrong role.

Step 1: decide whether you mean a speech/theme or an important annotation.
Step 2: insert keynote (one word) for speeches/themes/verbs; insert key note (two words) for important notes/comments.
Step 3: reread and adjust surrounding words so the sentence sounds natural.

Original: The head will key note the meeting tomorrow.
Rewrite: The head will keynote the meeting tomorrow.
Original: Put a keynote on the bibliography.
Rewrite: Put a key note on the bibliography.
Original: Is that the key note of the conference?
Rewrite: Is that the keynote of the conference?

A simple memory trick

Link the form to meaning, not sound. Picture keynote as one unit when you mean a speech or theme. Picture key + note as two units when you mean an important annotation.

Speech/theme = one unit → keynote.
Important comment/annotation = two units → key note.
Search your drafts for both forms and correct them in bulk to reinforce the habit.

Similar mistakes to watch for

Once spacing or hyphenation errors appear, related slips often follow. Scan nearby text for other split or fused words and for misplaced hyphens.

other split words (e.g., any more vs anymore)
hyphen confusion (e.g., long-term vs long term)
verb-form confusion (e.g., to record vs record as noun)
word-class confusion (adjective vs noun uses)

FAQ

Should I hyphenate 'key-note' in a headline?

No. Modern usage favors keynote (one word) in headlines. Use a hyphen only if a specific style guide requires it.

Is 'to keynote' a correct verb?

Yes. To keynote (one word) is a standard verb meaning to deliver the main address: "She will keynote the forum."

Can 'key note' ever mean the same as 'keynote'?

Rarely. Key note usually means an important note or remark; keynote normally means the main speech or theme. Context can clarify, but these are distinct senses.

Which is correct: 'keynote speaker' or 'key note speaker'?

'Keynote speaker' (one word) is correct for the main presenter. 'Key note speaker' would suggest a speaker who gives an important note-an unusual and likely unintended meaning.

Quick edit: 'add a key note about sources' - should I change it?

If you mean "add an important annotation about sources," keep key note. If you mean "add the main talk about sources," change to keynote. When uncertain, rewrite: "Add an important note about sources."

Need a fast check?

When unsure, run the two quick tests above: speech/theme → keynote; important note/annotation → key note. Paste your sentence into a checker or try a short rewrite-rewrites often clear the ambiguity fastest.