Three Important Aspect of Paragraph Structure

In the previous article, it has been stated that a paragraph is:

Several sentences (probably simple, compound, and complex sentences) that are connected to each other in making a single subject

The term subject in this understanding is a single topic. Thus, a good paragraph consists of a single topic that is expressed by the sentences themselves. Have a look for the following paragraph that talks about Gold, from the Book of Writing Academic English NY, Longman.

Gold, a precious metal, is prized for two important characteristics. First of all, gold has a lustrous beauty that is resistant to corrosion. Therefore, it is suitable for jewellery, coins, and ornamental purposes. Gold never needs to be polished and will remain beautiful forever. For example, a Macedonian coin remains as untarnished today as the day it was made 25 centuries ago. Another important characteristic of gold is its usefulness to industry and science. For many years, it has been used in hundreds of industrial applications, such as photography and dentistry. The most recent use of gold is in astronauts' suits. Astronauts wear gold-plated heat shields for protection when they go outside spaceships in space. In conclusion, gold is treasured not only for its beauty but also, for its utility.

From this paragraph, it is obvious that the author exactly wants to tell the readers about the importance of gold which are expressed with two factors, i.e.:

• gold has a lustrous (glowing) beauty that is resistant to corrosion
• gold has usefulness both in industry and science

Clearly speaking, the paragraph talks about why gold is very important for human being, which is also expressed in the last sentence, which is 

Gold is treasured not only for its beauty, but also for its utility

So, what does this mean? A good paragraph has a single topic - in this case, the importance of gold - which is written in a sentence of

Gold, a precious metal, is prized for two important characteristics.

Note that, in this sentence, the author appears to write only with a subject and a verb. Given that this type of sentence equals to simple sentence; therefore, to control the topic within a paragraph, it is suggested to use a simple sentence. What is a simple sentence? we already have discussed it in the previous article. For you who want to understand more, it is advised to visit this Clauses - Simple, Compound, and Complex Sentence.

Gold, (is the topic), a precious metal, is prized for two important characteristics (the controlling idea)

So, in this first sentence, the simple sentence has the function to control the paragraph to only talk about gold and two important characteristics.

In order to support the gold and two important characteristics, the supporting sentences are used. That is, they explain and prove why the gold has two important characteristics, and they are:

First of all, gold has a lustrous beauty that is resistant to corrosion

Is it true that a gold has a lustrous beauty? what is the prove of its resistance to corrosion?

The author gives an example with the word

For example, a Macedonian coin remains as untarnished today as the day it was made 25 centuries ago

And another sentences that are used to state the other important characteristics is

Another important characteristic of gold is its usefulness to industry and science

Conclusion

Thus, in making a good paragraph, you should have had one topic sentence, and try to control the topic by limiting the explanation via "Simple sentence". Then, try to support the sentences with "Supporting Sentences" to explain and prove the topic and controlling idea. And the last one is "Compound Sentence" that are used in describing the topic.