Joy Aloisi recently asked me to explain the difference between transitive and intransitive verbs. I am sure a lot of nonlinguists have wondered about the same thing so it occurred to me that I might do a short note about this distinction here that I can refer to in the future.
The problem in explaining this difference is that you have to know two other grammatical functions in order to understand this one: Subject and Object. The subject is usually the first noun or noun phrase in a sentence, the thing that the sentence is about. In the sentence John ran, John is the subject. In the sentence, The big girl in the ragged jeans left, The big girl in the ragged jeans is the subject. John and the big girl are what their respective sentences are about.
John and the big girl . . . are the subjects because that is their relationship to the verbs in their respective sentences (ran and left). “Subject” and “Objects” are relationships to the verb. So what is the “Object”?
The Object of a sentence is the noun that refers to something that the subject does something to. In the sentence, John bit the dog, John, again, is the Subject and the dog is the Object. In the sentence Sarah sipped the soda, the soda is the Object.
Now, if you know what Subjects and Objects are, you are in a position to understand what transitive and intransitive verbs are. All verbs in English have Subjects. You can’t say simply Rains in English (you can in Russian) because all verbs demand a Subject in English. The default Subject in English is it, so we have to say It rains or (is raining).
Objects are different, however. A few verbs MUST have Objects, e.g. devour and interject: you can’t say Mabel devoured or Fred interjected without an Object somewhere in the sentence. These verbs are strictly transitive.
Other verbs CANNOT have Objects. You cannot, for example, arise anything; something just arises. You can’t inquire anything; you just inquire or inquire about something (prepositional phrase). These verbs are strictly intransitive and intransitive verbs are often associated with a particular type of prepositional phrase that behaves a lot like an Object.
Other verbs may or may not have Objects. So you can just walk or you can walk the dog, you can just eat or you can eat supper. These verbs are ambitransitive: transitive when they have a direct object, intransitive when they do not.
This is all there is to it—well, the basics anyway.