Definition: A verb that is used without a direct object, or a verb that does not need a direct object to express a complete thought.
Some verbs can be used only as transitive verbs, but other verbs can be used both transitively and intransitively, depending on the meaning. An example of a verb that can be either transitive or intransitive is "to study" and its Spanish equivalent, estudiar. In the sentence "Tomorrow I am going to study" (Mañana voy a estudiar), the verb is intransitive; it indicates only the action without indicating the recipient of the action. But in the sentence "I studied the history books" (yo estudiaba los libros de historia), the verb is used transitively.
Examples:
Verbs in boldface in these sentences are typically used intransitively: The baby crawled toward the corner. (El bebé gateó hasta el rincón.) He did not sleep for two days. (No durmió durante doce días.)
