Subject and Topic

The terms subject and topic are often used in semantics. Sometimes the subject and topic are the same but not always. Let us illustrate with an example.

The sentence The pencil is on the table consists of a subject (the pencil) and a verb phrase. The verb phrase can further be divided into a verb phrase (is) and a prepositional phrase (on the table). However, the sentence can be used to emphasize different information. If one hears the question What's on the table? it's sufficient to answer The pencil. But if one hears the question Where's the pen? it's sufficient to answer On the table.

In the sentence The pencil is on the table the subject is the pencil. In response to the question What's on the table? the phrase the pencil is also the topic. However, in response to the question Where's the pencil? the topic of the sentence is on the table. In this case the subject and the topic are different.

In English the subject usually occurs at the front of the sentence because English has SVO order. The topic, however, can occur in either subject or object position and is the focus of the conversation. Languages such as Japanese and Korean have separate markers to indicate the subject and topic of the sentence.