Topic Sentences
Where they are found and what they do.
A
topic sentence is the central idea of a
paragraph. It is an overview of what
readers should see in a single paragraph.
 Think
of a topic sentence as
the umbrella
for the paragraph:
it
the information contained in
the paragraph
Why do we use topic
sentences?
To help readers
 by allowing a
reader to know
exactly what they
are going to find in
a paragraph
Why do we use topic
sentences?
To help writers
•by providing writers with a way to organize their
thoughts and ideas

Look at this paragraph and think about the main
idea:

The rain forest is home to many creatures. Monkeys,
toucans and macaws live in the rain forest. Blue
Morpho butterflies and anteaters also live in the rain
forest.

The animals described in the above paragraph are
examples of the different creatures that can be found
in the rain forest. The topic of this paragraph comes
in the first sentence which explains that a variety of
animals can be found in the rain forest.
Sample Paragraph No. 1

Now think about the next paragraph and once again
consider the topic:

There are many fun things to do at the beach.
Swimming is one thing that can be done at the beach.
Snorkeling is another thing that can be enjoyed.
Playing beach volleyball can be a lot of fun. It is also
fun to look for shells. Some people simply like to
sunbathe.

The first sentence is the topic. It explains that there
are many things that we can do at the beach. The
other sentences describe what these things are.
Sample Paragraph No. 2
swimming
snorkeling
Things to do
at the beach
volleyball
Looking for
shells
sunbathing
Sample Paragraph No. 2

Now consider the following paragraph:

Talk about bad days: today is a classic. First, I
woke up to hear my parents yelling in my ear
because I didn’t clean my room. Then I went to
school to find out I had failed my science project.
At lunch, while walking out of the cafeteria I
tripped over somebody’s bag and made myself
look like a fool. Finally, I came home to learn
that I might have my I-Pod taken away, and it
wasn’t even my fault! And it’s only two in the
afternoon!
Sample Paragraph No. 3
Parents screaming
Failed science project
Having I-Pod taken
away.
Today is a classic
bad day
Tripped
Sample Paragraph No. 3

My life is full of risks. As a stair builder
who works with heavy machinery, I risk
cutting off a finger or a limb every day.
Each Monday and Thursday, I risk four or
five dollars on the state lottery. Every
time I take my beat-up, 1981 Chevy
Caprice Classic for a drive, I risk a break
down. However, the biggest risk I’ve ever
taken was my decision to attend DeVry
Institute this year.
Sample Paragraph No. 4
What is the central idea?
?
What are the supporting ideas?
?
?
?
?
Sample Paragraph No. 4

No, not always. Sometimes there is no
one sentence that summarises the main
idea. In this case you should read the
whole paragraph and think about what
the general idea is.
Are topic sentences always the
first sentence of a paragraph?
In 1951 Henrietta Lacks died of cancer. Her cells,
however, are still alive today. They are studied in
cancer-research laboratories all over the world.
Rarely do cells continue to grow once they are
separated from a living body. But the cancer cells
which killed Henrietta Lacks only eight months after
the disease was detected were so potent, they
survive today. HeLa cells- the name is derived from
the first two letters of Henrietta’s name- were
instrumental in the development of a vaccine against
polio. Ultimately researchers hope that the HeLa cells
will lead them to a cure for cancer.
 Is this paragraph about:
◦ a. Henrietta Lacks
◦ b. cancer cure
◦ c. HeLa cells

Sample Paragraph No. 6

Sometimes the topic sentence is the last
sentence of a paragraph.

I can’t help but marvel in awe. The students at
Odyssey are truly a cut above the rest when it
comes to character. Not only do they accept all
people, but they strongly support them. When one
student struggles in a subject, other students jump
in to help. Often, when someone is having a bad
day, students steer clear, but not at Odyssey.
These students do what they can to uplift others
spirits. A low rumble of teamwork is the noise you
will hear at Odyssey. Students work together to
promote learning and their noise levels are
respectful to others concentration. The superior
quality of character at Odyssey makes it a
wonderful place to learn.
Sample Paragraph No. 5
What is the central idea?
?
What are the supporting ideas?
?
?
Sample Paragraph No. 5

One early theory likened human memory to a muscle
that had to be regularly exercised in order to function
properly. This theory was eventually replaced by the
notion that remembering was like writing, with
experience the pen and the mind a blank page. But
eventually this theory was also rejected. In its place
came another hypothesis- that human memory
functioned with a complex and well-stocked library
catalogue. With access to a key word you could look
up any piece of stored or catalogued information. But
over time that theory has also been discarded.
Human memory may in fact be too sophisticated and
too complex to be explained through any one single
simile or metaphore.
Sample Paragraph No. 7