Topic Sentences and Controlling Ideas

Every topic sentence will have a topic and a controlling idea. The controlling idea shows the direction the paragraph will take.

Here are some examples:

• Topic Sentence: There are many reasons why pollution in ABC Town is the worst in the world.  
• The topic is “pollution in ABC Town is the worst in the world” and the controlling idea is “many reasons.”

• Topic Sentence: To be an effective CEO requires certain characteristics. 
• The topic is “To be an effective CEO” and the controlling idea is certain characteristics. 

• Topic Sentence: There are many possible contributing factors to global warming.
• The topic is "global warming" and the controlling factor is "many possible contributing factors." 

• Topic Sentence: Fortune hunters encounter many difficulties when exploring a shipwreck.  
• The topic is “exploring a shipwreck” and the controlling idea is “many difficulties.”

• Topic Sentence: Dogs make wonderful pets because they help you to live longer. 
• The topic is "dogs make wonderful pets" and the controlling idea is "because they help you to live longer."

• Topic Sentence: Crime in poverty-stricken areas occurs as a result of a systemic discrimination. 
• The topic is "crime in poverty stricken areas" and the controlling idea is "systemic discrimination." 

• Topic Sentence: Teen pregnancy may be prevented by improved education.
• The topic is "teen pregnancy may be prevented" and the controlling idea is "improving education."

• Topic Sentence: Cooking requires a number of different skills.
• The topic is "cooking" and the controlling idea is "many different skills."

• Topic Sentence: It is important to be ready before buying a house.
• The topic is "before buying a house" and the controlling idea is the importance of being ready. 

• Topic Sentence: Graduating from high school is important for many different reasons.
• The topic is "graduating from high school" and the controlling idea is "many different reasons."

• Topic Sentence: Having a first child is difficult because of the significant adjustments in your life. 
• The topic is "having a first child" and the controlling idea is "significant adjustments in your life."

• Topic Sentence: Remodeling a kitchen successfully requires research and a good eye. 
• The topic is "remodeling a kitchen" and the controlling idea is "requires research and a good eye." 

As you can see, the topic sentence provides a focus for the reader or listener. It tells what the paragraph is about. The controlling idea helps the audience understand what you are saying.

Topic sentences can be about almost anything, as long as they set the tone for the paragraph and relate back to the thesis or the main idea of the paper.