What aspect of voice indicates a subject performs the action in the sentence?

The aspect of voice that indicates a subject performs the action in the sentence is the active voice. In active voice constructions, the subject is clearly the doer of the action, which leads to more direct and vigorous sentences. For example, in the sentence "The manager approved the project," the subject (the manager) is performing the action (approving).

Using the active voice typically clarifies the writing by making it straightforward for the reader to understand who is doing what. This clarity is essential in business writing, where concise and effective communication is paramount. In contrast, other voices like passive voice diminish the immediacy of the action by obscuring the subject or making it the receiver of the action, which can lead to ambiguity or weakened statements.