Comma After Yes and No
Initial yes and no often function as introductory response words rather than as grammatical parts of the clause that follows, so edited prose normally separates them with a comma. Chicago also notes that equivalent introductory phrases can take the same treatment. The rule is functional: yes/no inside another construction does not automatically receive a comma.
When “yes” or “no” begins a sentence as a standalone response or introductory word, it is normally followed by a comma: “Yes, I agree.” “No, that is not the issue.” Stronger punctuation can be used for emphasis. Do not add a comma mechanically every time the words yes or no appear.
Key details
Further guidance
Basic Pattern
Use a comma when “yes” or “no” stands at the beginning as an introductory response: “Yes, the figures are final.” “No, we have not approved the change.”
Not Every Yes Or No
Do not use this as a word-only rule. In “a yes-or-no question,” for example, yes and no are part of a compound expression rather than introductory responses.
Stronger Emphasis
A period, exclamation point, or dash can replace the comma when the response is intentionally more emphatic or sharply separated: “No! That is not what I meant.”
Why The Comma Works
The comma separates the introductory response from the clause that follows. Purdue includes “yes” among introductory words normally followed by a comma, and Chicago treats yes/no and comparable introductory phrases similarly.
Worked Examples
Standard: “Yes, I can send the file today.” Standard: “No, the meeting has not moved.” Emphatic: “Yes! That solves it.” Non-introductory: “Please give me a yes-or-no answer.”
Sources and evidence
Sources are shown with the role they play in this guide. Historical or style-sensitive claims are kept within the evidence boundary described above.
- Commas Q&A — yes/no equivalents (opens in a new tab)The Chicago Manual of Style · Current CMOS 18 guidance says sentence-initial yes or no, and phrases functioning similarly, can normally be followed by a comma; stronger punctuation may be chosen for emphasis.
- Extended Rules for Commas — Purdue OWL (opens in a new tab)Purdue University · Direct punctuation guidance for commas in geographical names and addresses.