Comma When the Verb Is Omitted in a Compound Sentence
The Comma
Rulebase Summary
Use a comma to mark the spot where a verb has been omitted from a compound sentence when the idea is readily understood without it. The comma shows the reader where the missing verb would be. The comma of omission replaces the missing coordinate conjunction in compound dependent constructions.
Examples
A. The first witness testified on Monday; the second on Wednesday.
A. The first witness testified on Monday; the second, on Wednesday.
Comma marks where the omitted verb 'testified' would be.
A. His office was on the third floor; hers on the fifth.
A. His office was on the third floor; hers, on the fifth.
Comma replaces the understood verb 'was.'
Transcript Notes
The coordinate conjunction, though it links two elements together, also keeps them apart — it acts as a signal that the elements are separate and distinct. When the conjunction is missing and we need to show separate elements, the comma of omission fills the role. This rule applies ONLY to compound dependent constructions. Using a comma of omission between independent clauses (where a conjunction is missing) creates a run-on sentence — this must be avoided at all costs.
Style Guide References (3)
Morson's
BGGP
BGGP