Going straight to the main idea of each paragraph significantly increases your reading speed. This main idea is the paragraph's topic sentence. You don’t have to read as much to get a firmer grasp of the author’s fundamental ideas if you can find and understand a paragraph's topic sentence. The question is: How do you recognize the main idea in a paragraph amid all the details?
Understanding topic sentences
The topic sentence describes the subject of the paragraph and its main idea. If you can develop a nose for locating topic sentences, you can get the main idea from paragraphs quickly and thereby improve your reading speed and comprehension.
Typically, the topic sentence comes first in a paragraph, and the remaining sentences elaborate on the topic sentence. In the following paragraph, for example, the topic sentence makes a simple assertion, and evidence for its truth follows on the heels of the topic sentence:
Rainfall has been increasing steadily in Yoknapatawpha County since 1995. In that year, annual rainfall was 32 inches. By 2008, it was 40 inches, with an increase each year between 1995 and 2008, except for 1999, when the annual rainfall level fell to 29 inches.
But sometimes the topic sentence isn’t the first sentence in the paragraph. Sometimes it’s buried deeper. In this paragraph, the second sentence is the topic sentence:
Looking at rainfall in Yoknapatawpha County since 1995, a clear trend is evident. Except for 1999, when the annual rainfall level fell to 29 inches, rainfall has increased steadily since 1995. Between that year and 2008, rainfall rose from 32 to 40 inches annually.
The author of the following paragraph is a bit of a windbag and takes his time getting to the main idea. In this paragraph, the topic sentence is the last sentence:
Is it getting wetter or drier in Yoknapatawpha County? A quick look at the record gives a clear answer. Between 1995 and 2008, rainfall rose from 32 to 40 inches annually (although in 1999 it dipped to 29 inches). From this information, it’s plain to see that rainfall in the county has increased steadily since 1995.
Locating the topic sentence
Because the topic sentence can be located anywhere, how can you spot the topic sentence and get to the main idea in a paragraph? Here’s how:
Read the first sentence carefully. Three times out of five, the topic sentence is the first sentence.
Consider what basic property or characteristic the paragraph describes. This attribute is the paragraph’s main idea, so the sentence that expresses it is your topic sentence.
Think about the paragraph’s purpose. The paragraph most likely wants to impart a particular piece of information. If you can figure out what that piece is, you know the paragraph’s topic and can find the sentence that presents it.
Observe the author’s writing style to determine where she likes to put the topic sentence in paragraphs. Knowing your author’s style helps you locate the topic sentence faster.
