Every sentence contains a subject. The University of the Sciences defines the subject of a sentence as "the person, place, or thing that performs the action in a sentence or
tells what is spoken about in the sentence." For example, in the sentence, "The dog runs down the street," the dog is the subject of the sentence. A proper noun can also serve as the subject of a sentence. For example, in the sentence "The University of the Sciences has grammar information," the University of the Sciences is the subject of the sentence.
Every sentence must contain a verb in order to be a complete and logical sentence. For example, "The dog" is not a sentence, but instead could be classified as a phrase because it does not contain a verb. However, "The dog runs" is a complete sentence because it contains both a subject and a verb that describes what the dog is doing. When writing a sentence make sure to include a verb that agrees with the subject of your sentence.
According to the University of the Sciences, in a complete sentence the direct object is the object of the sentence that receives the action of the verb of the sentence. Although a direct object is not necessary in a sentence and is sometimes implied instead of stated, complete and detailed sentences usually contain a direct object. In the sentence, "The owner walked his dog," the dog is the direct object because it is the one being walked by its owner.
The indirect object is similar to the direct object of the sentence in that not all sentences contain indirect objects. However, many sentences that are complete and thorough contain an indirect object. Clarion University defines the indirect object as "a noun or pronoun that states to whom (or to what) or for whom (or for what) something is done. In the sentence "The owner bought his dog a bone," the dog is the indirect object because the bone or object of the sentence was bought for him.
Punctuation allows the writer of a sentence to provide clear information to the reader about how the sentence is supposed to be read and understood. In simple sentences with a subject, verb and direct object only a period, question mark or exclamation point is needed at the end of a sentence. However, when a compound sentence is written, commas, semicolons, colons or dashes often need to be incorporated to help the reader understand what the sentence is trying to portray and to clarify how the sentence should be read on the page.