The topic sentence is the main point, or main idea of a paragraph. The topic sentence should identify the main idea and point of the paragraph. To choose an appropriate topic sentence, read the paragraph, and think about its main idea and point. The supporting details in the paragraph (the sentences other than the topic sentence) will develop or explain the topic sentence.
A topic sentence essentially tells readers what the rest of the paragraph is about. For example, if the topic sentence concerns the types of endangered species that live in the ocean, then every sentence after that needs to expound on that subject. Topic sentences also need to relate back to the thesis of the essay. If you cannot identify the topic sentence of a paragraph, your comprehension will suffer since you will not be able to understand the author's main idea.
The following four steps will help you identify the topic sentence-
Step 1. Find the topic of the paragraph-
Do not confuse the topic with the topic sentence. The topic is simply the who or what being discussed in the paragraph, while the topic sentence includes the topic and the point being made about it. Knowing the topic will point you towards the topic sentence. Circle the words used most often in the paragraph. Also, circle any synonyms or pronoun references.
Step 2. Identify the keywords that signal a topic sentence-
While not all topic sentences include keywords, when you come across sentences with any of these phrases, you can be fairly certain that it is the topic sentence.
Step 3. Identify the major details-
Sometimes, the supporting details are easier to find than the topic sentence. If so, identify all major details, and see what they have in common. This is an especially effective technique for paragraphs that do not have an explicitly stated topic sentence.
Step 4. Look beyond the first sentence to identify the topic sentence-
Do not assume that the topic sentence is the first sentence of the paragraph. In most paragraphs, the topic sentence is one of the first sentences; however, that is not always the case. Sometimes, the writer includes some introductory material before getting to the point, or the writer sums up the major details with a topic sentence at the end.
For example, look at the following paragraph-
“Most environmental scientists agree that human activity directly contributes to global warming. Luckily, most also agree that human activity also has the potential to reverse global warming. There are several changes that average Americans can make to lower their carbon footprints. The first change they can make is to reduce, reuse, and recycle as often as possible. A large amount of pollution is expelled in the production of new products; whereas, it requires no additional fossil fuels to reuse an item. Recycling, while still using fossil fuels to reprocess the product, consumes much less energy than creating a new item from scratch. Using public transportation is another way that Americans can reduce their carbon footprints. Cars are the single biggest contributor to greenhouse gases. Walking to work and school is even more beneficial. Lastly, more Americans can adopt alternative energy sources. Installing wind turbines and solar panels reduce our reliance on fossil fuels, which will reduce the harmful emissions they cause. By adopting all three of these changes, Americans can help ensure a brighter future for generations to come.”
Even though the first sentence has a solid main idea that could be the topic of a paragraph, namely that humans cause global warming, the rest of the paragraph is not about that topic. Following the steps outlined above helps identify the topic sentence.
Step 1. Find the topic of the paragraph- The topics are Americans, global warming, and change.
Step 2: Identify the keywords that signal a topic sentence- See in the above paragraph text, as "There are a several changes"
Step 3: Identify the major details- As, [i] Americans need to reduce, reuse, and recycle. [ii] Americans need to use transportation other than cars. [iii] Americans need to adopt alternative energy sources.
What do all of these major details point to? Americans can make specific changes to help global warming.
Step 4: Look beyond the first sentence to identify the topic sentence- In this case, the topic sentence is the third sentence. "There are a several changes that average Americans can make to lower their carbon footprints."
Develop a topic sentence-Use these guidelines to help you develop effective topic sentences of your own.
a) Know what you want to write and the point you want to make about it.
b) When appropriate, incorporate the above keywords into your topic sentence to signal its location to your reader.
c) Develop major details to support your topic sentence and vice versa.
d) Place the topic sentence early in the paragraph. This is not mandatory, but it is a strategy that will ensure that you consciously have a topic sentence in your paragraph to guide you as you write.
For example-
If you had an assignment to develop a topic sentence for a process paragraph where you need to outline the steps in the rock cycle, the topic sentence might look something like this; There are three steps in the rock cycle; as- [i] igneous [ii] sedimentary [iii]metamorphic.
Classification and types of topic sentences-
Topic Sentence is usually the first sentence and introduces the main idea, whereas sometimes introduces the details.
Types of Topic Sentences-
[1] General Topic Sentence-
Names the main idea of the paragraph. Not specific.
Examples of a General Topic Sentence
The hot trend in advertising these days is to hire real, live stars.
Kevin James would have been 20 years old this September.
[2] Clueing Topic Sentence-
Names the main idea of the paragraph. This type of topic sentence gives a "clue" about the details of the paragraph. This type gives a "hint" about what the paragraph is about! Examples of a Clueing Topic Sentence are-
The four seasons spice up our lives.
Tents come in a variety of shapes and sizes.
The citizens of Lawrence have several reasons for building a new high school.
[3] Specific Topic Sentence-
Names the main idea of a paragraph, but names the specific details to be covered in order. Example of Specific Topic Sentences-
Air pollution is caused by vehicles and industries.
Charles Darwin lived an interesting life as an explorer, writer, and scientist.
Diseases caused by vitamin deficiencies are beriberi, pellagra, and scurvy, and rickets.