A Concise Guide to English Grammar

Chapter 10 introduced tense and aspect—the systems that locate events in time and describe their internal structure (completed, ongoing, habitual). But time is not the only thing speakers need to express about events. Consider a sentence like She wrote the report. This tells you what happened and when. Now compare: She might write the report, She must write the report, The report was written by her. Each version adds a different layer of meaning to the same basic event. The first signals possibility; the second signals obligation; the third rearranges who appears as the subject. These are the two systems this chapter explores: modality (the speaker’s attitude toward the event) and voice (how the participants of the event are mapped onto grammatical positions).

Modal auxiliaries are a small set of verbs—can, must, should, will, and others—that appear before the main verb to express the speaker’s attitude toward an action. They signal meanings like ability, possibility, obligation, and permission without changing when the event happens.

Not every language handles modality the way English does. Spanish, for example, has a dedicated future tense conjugation (hablaré means “I will speak”) built directly into the verb’s ending, where English must use the modal auxiliary will as a separate word. Spanish also uses a verb mood called the subjunctive (Es posible que hable, “It’s possible that he speak”) to express doubt, possibility, and desire—meanings that English conveys through modals like might or could. Where English says She might come, Spanish shifts the verb itself into a different conjugation pattern. The result is the same kind of meaning expressed through fundamentally different grammatical machinery.

Voice describes how the participants of an action are mapped onto grammatical positions. In active voice, the doer is the subject; in passive voice, the receiver is the subject. The event stays the same—only the framing changes.

Voice works differently across languages, too. English marks the passive with a form of be plus a past participle: The letter was written. But not every language builds a passive this way, and some barely use one at all. Mandarin Chinese, for instance, has no verb morphology for passive—verbs do not change form. Mandarin can use the particle bèi (被) to mark a passive-like construction (Xìn bèi xiě le, roughly “The letter BEI written”), but this construction historically carried a connotation of adversity—something bad happening to the subject—and speakers often prefer to simply rearrange word order or leave the actor unspecified rather than use a passive marker at all. The fact that English has a fully productive passive voice—applicable to virtually any transitive verb, in any tense—is a distinctive feature, not a universal one.