What is a Paragraph?

A paragraph is a group of related sentences whose purpose is to express one basic idea.

Normally, a paragraph is part of a series of paragraphs, which work together to express a larger, more complicated idea (also called a "thesis").

All the sentences in a paragraph should be closely connected to the central idea. The introductory sentence (or "topic sentence") states the idea. The following sentences (supporting sentences) support or expand the idea. The concluding (=last) sentence usually summarizes the idea of the paragraph.

Well-written paragraphs will be clear. They will lead your reader to accept what you are saying as true.

Here's an example of a strong paragraph:

(Topic sentence:) The characteristics of the main study variables, namely alcohol intake and coronary heart disease, differ between men and women. (Supporting sentences:) Women, for example, do not have the same coronary heart disease risk profile. Drinking patterns in men and women also differ in terms of both the type of beverage and the quantity. The metabolism of alcohol is also different in women and men. (Concluding sentence:) Therefore, all these analyses have considered men and women separately.

This is easy to follow. It uses simple, short sentences. 

Now, go and try to write your own paragraphs!!