Voice is a grammatical category, an operator, that has no directly link to conceptual structure. Voice is a complex issue, but it appears to mark a prominent object that the speaker chooses to make ...

When the subject of a sentence isn't doing something, the verb is passive. On the other hand, a sentence is active when the subject performs the verb (action). For example, in this sentence the ...

This structure is used to report information in a formal style or to report facts. Passive structures hide the source of the information. This is because a) it is obvious b) the source is ...