Breaking down a sentence, also called diagramming a sentence, is a skill most students learn in school. It involves separating a sentence into its component parts: subject, object, verbs, prepositional phrases, adjectives, adverbs and articles, among other things. Diagramming a sentence can be a difficult thing to learn, but also can help you understand why some sentences work better than others. Once you learn how to do it, it is difficult to look at a sentence without separating it into its component parts.
Identify the verb in the sentence. The verb is the main action that takes place. In the sentence "Bob closed the door," "closed" is the verb. Be careful not to be fooled by action words that perform a different function in the sentence. For example, in "Running is hard work," "Running" is a noun, while "is" is the sentence's main action.
Identify the sentence's subject. The subject is the person or thing that performs the verb. In the examples above, "Bob" and "Running" are the subjects that perform the verb. The subject can be a group of words. In the sentence "Jack and Melissa looked at the stars," the subject is "Jack and Melissa."
Identify the direct object of the sentence. The direct object is the person or thing on which the sentence's actions is performed. In "Bob opened the door," "the door" is the direct object, the thing that Bob opened. Note that only transitive verbs take a direct object. If a verb is used intransitively, there is no direct object to identify. For example, "Andrea slept 10 hours" contains no direct object because Andrea does not sleep in or on anything.
Identify adjectives and adverbs. Adjectives and adverbs describe objects and verbs. The sentence "Jack and Melissa looked at the stars" contains no adjectives and adverbs. The adjective "bright" and the adverb "carefully" describe an object and a verb: "Jack and Melissa looked carefully at the bright stars."
Identify prepositional phrases. Prepositional phrases describe how a verb is performed; they begin with a preposition, words such as "on," "in," "around" and "about." For example, in the sentence "Andrea slept on a bed," "on a bed" is a prepositional phrase. It describes place and shows how the sleeping is performed. The object in a prepositional phrase (in this case, "bed") is also called the indirect object.