Transitive verbs require a direct object to complete their meaning ("She wrote a letter"), while intransitive verbs are complete without an object ("The cat slept"). Some verbs function as both—"read" is transitive in "I read the book" and intransitive in "I read." Understanding transitivity helps clarify whether a verb can take an object.
Test a verb by asking "What?" or "Whom?" after it. If the question needs an answer, the verb is transitive. "She wrote what?" (a letter) = transitive; "The cat slept what?" (no answer) = intransitive.
From your study of verbs, you know that a verb expresses an action or state. Transitivity describes whether that action reaches out and touches something else — whether it requires a receiver, or whether it is complete in itself. This distinction shapes sentence structure in ways that matter for writing clearly and for understanding grammar concepts ahead, like direct objects and passive voice.
A transitive verb carries its action across to an object. Think of it as a transfer: the action moves from the subject through the verb to something on the other side. "She threw the ball." The throwing doesn't just happen — it happens *to* the ball. The ball is the direct object, the thing that receives the action. If you remove it ("She threw."), the sentence feels unfinished — you want to ask "Threw what?" That incompleteness is the signal that the verb is transitive.
An intransitive verb completes its action without needing a receiver. "The baby laughed." Laughed what? The question doesn't make sense — the action is entirely contained within the verb. "She arrived." "He slept." "The stars shone." These verbs describe events that happen without transferring to an object. The sentence is complete as it stands.
The most important nuance is that many verbs can be both, depending on context. Consider "read": "She reads every night" (intransitive — no object, the reading is self-contained) versus "She reads mysteries" (transitive — mysteries is the object). The verb hasn't changed; the structure around it has. "Eat," "grow," "run," and dozens of other common verbs work this way. The same verb can be transitive in one sentence and intransitive in another, which is why transitivity is always a property of the verb *in a particular sentence*, not the verb in isolation. The test remains the same: ask "What?" or "Whom?" after the verb. If an answer is required for the sentence to feel complete, the verb is transitive. If no answer is needed, it's intransitive.