Every good paragraph has a topic sentence, which clearly states the topic and the controlling
idea of the paragraph. It is a complete sentence. It is usually but not always the first sentence in the
paragraph.
A topic sentence is the most important sentence in a paragraph. It briefly indicates what the
paragraph is going to discuss. For this reason, the topic sentence is a helpful guide to both the writer and
the reader. The writer can see what information to include (and what information to exclude). The reader
can see what the paragraph is going to be about and is, therefore, better prepared to understand it.
FEATURES OF A GOOD TOPIC SENTENCE
There are three important points to remember about a topic sentence.
1. A topic sentence is a complete sentence; that is, it contains a subject, a verb, and
(usually) a complement. The following are not complete sentences:
Driving on freeways.
The importance of gold.
How to register for college classes.
2. A topic sentence contains both a topic and a controlling idea. It names the topic and
then limits the topic to a specific area to be discussed in the space of a single paragraph. The
following examples show how a topic sentence states both the topic and the controlling idea in a
complete sentence:
Driving on freeways requires skill and alertness.
Gold, a precious metal, is prized for two important characteristics.
Registering for college classes can be a frustrating experience for new students.
3. A topic sentence is the most general statement in the paragraph because it gives only
the main idea. It does not give any specific details. The following is an example of a
general statement that could serve as a topic sentence:
The Arabic origin of many English words is not always obvious.
The following sentence, on the other hand, is too specific:
The slang expression so long (meaning "goodbye") is probably a corruption of the
Arabic soloom.
Sentences such as the following may be too general:

English is a difficult language to learn.