In formal writing, it is essential to express your argument clearly and logically.
As well as needing careful choice of language, this requires good paragraph
construction so that the reader is left in no doubt as to the points that the
writer wishes to make. Many writers choose to include a topic
sentence when they write a paragraph to ensure that the reader does not
miss the main point that is being made. Topic sentences can also help you as
a writer to construct a good paragraph. Effective topic sentences share certain
characteristics.
In these activities you will learn what the characteristics of a good topic
sentence are; study some examples of effective and ineffective topic sentences
and practise composing a topic sentence yourself.
Activity 1: Recognising the features of a topic sentence
Look at these three examples of topic sentences taken
from paragraphs in different subject areas and think about what general features
they have in common. Make some notes in the box below and check them at the
end of this activity to see whether you identified the features correctly.
It is important to observe some basic rules concerning the exchange of
business cards when doing business internationally.
The two operating positions of a tiny transistor switch are the basis
of the giant brainwaves produced by a computer.
The European marmot, like other species of marmot, is a social animal.
Now study this list of the important features of topic sentences. Check the
examples if necessary.
1. A good topic sentence contains a reference to the specific subject
or focus of the paragraph and expresses the main idea(s)
of the paragraph.
In this example, the topic sentence is in bold and the
main points in the paragraph that it refers to are italicised:
Marmota marmota is the Latin name for the European or alpine marmot, which
is one of fourteen species of this small mammal found in the northern hemisphere.
The European marmot, like other species of marmot, is a social animal.
It forms complex family groups each of which lives in a system
of burrows in sub-alpine pastures. A typical family group consists
of a male marmot, one or more females and a number of sub-adults and pups.
Strong bonds develop between family members as the young pups receive
support and protection from other members of the family but relations are
not always harmonious. Fighting can break out particularly between sub-adults
eager to establish their positions in the ranking order.
3. A topic sentence should always be a complete sentence.
A sentence requires at least a subject and a verb. The sentence below contains
a subject (The European marmot) and a verb (is) . It also contains a complement
(a social animal) and a comparison (like other species of marmot).
The European marmot, like other species of marmot, is a social animal.
4. A topic sentence should not be too narrow or too broad in meaning.
Like other marmot species, the European marmot lives in family groups,
in which the sub-adults sometimes fight each other to determine which is
dominant.
This sentence is too narrow to function as a topic sentence
for the paragraph above. While the statement is true it only specifies the
last point of the paragraph and does not cover the other main points of
the paragraph. The other main points all show the different ways in which
marmot behaviour reflects its social character. The topic sentence needs
to be wide enough in meaning to cover and link all the main points raised
in the paragraph.
The European marmot is an animal.
This sentence is too broad and, therefore, general in
meaning to be an effective topic sentence. The main points provide evidence
of the social character of the European marmot, not evidence that it belongs
to the animal kingdom. It is clear even from the first sentence that all
marmots are mammals and therefore animals.
Activity 2: Choosing the best topic sentence
Read the paragraph below and study these three sentences.
Select the one which is the best topic sentence for the paragraph.
Topic sentence 1: There are a number of recognised airborne pollutants
that are implicated in occupational asthma.
Topic sentence 2: Workers in certain environments need to be protected
from exposure to sensitising substances.
Topic sentence 3: Research into airborne pollutants and asthma has led
to a better understanding of the disease.
Consequently, certain work environments present a high-risk environment for
asthma sufferers. In the chemical and plastic industries, workers are frequently
exposed to airborne substances which are likely to trigger asthma attacks.
A recognised cause of occupational asthma are the isocyanates involved in
the production of polyurethane foam. These sensitising substances, as they
are called, can provoke a range of the typical symptoms of asthma such as
wheezing, chest tightness and shortness of breath, all resulting from the
effect of the irritants on the airway passages in the lungs of the sufferer.
Similarly, in the electronics industry the fumes given off by colophony during
soldering processes are known to trigger asthma.
There are a number of recognised airborne pollutants that
are implicated in occupational asthma.
This is the best topic sentence since the paragraph identifies some specific
airborne pollutants in different workplaces and their effects on asthma
sufferers. There is no evidence to support the second sentence in the paragraph
and the third sentence is only a conclusion that the reader might draw from
the paragraph and therefore it could not function as a topic sentence.
Activity 3: Composing a topic sentence
Read this paragraph and identify the points it contains. Then write a suitable
topic sentence in the space provided.
This range of activities includes, firstly, market research to find out if
and where groups of new customers exist, what their needs are, which of those
needs can be met, and how they can be met. Once market research has been carried
out, other marketing activities can be employed, such as analysing the competition,
positioning a new product or service in the market, pricing the products and
services, and promoting them through advertising, promotions, public relations
and sales.
When you are satisfied with your sentence compare it
with the topic sentence suggested below. How similar are they?
This paragraph briefly outlines activities pertaining to both market research
and to marketing generally, though it emphasises the importance of customer
needs within marketing.
A possible topic sentence is: Marketing includes a wide range of activities
aimed to ensure that a company or organisation can meet the needs of its
customers.