absolute phrases: comma use

Commas with an absolute phrase, a phrase with its own subject that describes the circumstances of the main clause.

Set off an absolute phrase with a comma, or with two commas when it interrupts the main clause: The inspection completed, we reopened the building. The phrase the inspection completed gives the circumstances under which we reopened the building. It has its own subject, inspection, but no finite verb.

An absolute phrase usually contains a noun or pronoun followed by a present or past participle: Rain falling steadily, we postponed the match. Their applications approved, the researchers began work. In the first sentence, falling describes what the rain was doing; in the second, approved describes what had happened to the applications.

A participle is not required. An adjective or a prepositional phrase can complete the construction: Her hands unsteady, Priya set down the glass. The guard stood beside the entrance, a radio in his hand. The absolute phrases describe circumstances accompanying the main action.

Place the comma at the boundary between the absolute phrase and the main clause. At the beginning, follow the phrase with a comma: The roads now clear, deliveries resumed. At the end, put a comma before it: Deliveries resumed, the roads now clear. In the middle, use both commas: The drivers, their vehicles fully loaded, waited for the gates to open.

An absolute phrase differs from a participial phrase, which describes the subject of the main clause. Checking the figures, Lena found an error opens with a participial phrase: Lena is the one checking. The figures checked, Lena submitted the report opens with an absolute phrase: it has its own subject, figures. Both phrases take a comma.

An absolute phrase has no finite verb. Adding one turns it into an independent clause: The repairs finished is an absolute phrase; The repairs were finished is an independent clause.

Examples

Use The last visitor gone, the attendant locked the doors. (The introductory absolute phrase takes a following comma.)

Use Malik waited outside, his coat folded over his arm. (The final absolute phrase takes a preceding comma.)

Use The witnesses, their accounts recorded, were allowed to leave. (Both commas mark the boundaries of the inserted absolute phrase.)

Avoid Her ankle swollen Maya could not wear the boot. (Put a comma after swollen to separate the absolute phrase from the main clause.)