Composition – JSS1 English Lesson Note (Third Term)

An expository essay explains a topic clearly and gives facts, reasons and examples. It does not tell a story or argue for one side. This lesson uses a short article on the benefits of planting trees to show students how an expository essay is organised and how to pick out its main points before writing.

Behavioural objectives

By the end of the lesson, students should be able to:

• say what an expository essay is;
• name the three parts of an expository essay;
• state why trees are important to life;
• explain how trees clean the air, save water and protect the soil;
• pick out the main points of an article as the basis for an essay.

What is an expository essay?

An expository essay gives information about a topic. The writer explains how something works, why it matters or what it involves. Examples of topics are “The importance of water” and “The benefits of planting trees”.

What are the parts of an expository essay?

• Introduction: states the topic and tells the reader what the essay will cover.
• Body: has one paragraph for each main point. Each paragraph begins with a topic sentence, followed by facts and examples.
• Conclusion: ends the essay by restating the main idea in a few sentences.

How do you plan an expository essay?

1. Read the topic and decide what it asks you to explain.
2. List the main points you will cover.
3. Write one or two facts or examples under each point.
4. Put the points in a sensible order.
5. Write the introduction, the body paragraphs and the conclusion.
6. Read your work and correct errors in spelling, punctuation and grammar.

Sample expository article on trees

How do trees support life?

Trees give humans and animals food, fuel, timber and shelter. During photosynthesis, trees use carbon dioxide, water and sunlight to make carbohydrates, and they release oxygen. The carbohydrates support the growth of fruits eaten by people, such as mangoes and oranges, and of leaves eaten by animals. Trees also give wood and charcoal for fuel and timber for building. They are a home for bees, birds and squirrels.

How do trees help to control the climate?

Trees take in carbon dioxide and release oxygen, which improves the quality of the air. They give shade to homes and streets, and they release water vapour into the air, which cools the surroundings. Rows of trees also act as windbreaks and reduce the force of strong winds and heavy rain.

How do trees clean the air and protect the soil?

Trees absorb harmful gases such as nitrogen oxides. They also trap dust and other particles in their leaves and bark. Their roots hold the soil in place and reduce soil erosion during floods.

How do trees save water?

When it rains, trees soak up water and store it in the soil around them. Their shade slows the evaporation of water from the ground. Leaves and branches also break the fall of rain, so water reaches the ground more gently and carries less dirt into streams and rivers.

How do trees create economic opportunities?

Planting trees creates jobs such as fruit harvesting, watering, building, furniture making and the production of paper and books. Trees planted near buildings give shade, which can reduce the need for fans and air conditioners and so save energy costs. Well-kept trees can also make a property more attractive and more valuable.

How do trees help health and mood?

Trees help people to relax. Their many shapes, sizes and colours lift people’s moods, and a calm, green place can help people to recover from stress.

Evaluation

1. What is an expository essay?
2. Name the three parts of an expository essay.
3. What is the name of the process in which trees use carbon dioxide, water and sunlight to make carbohydrates?
4. Which gas do trees release during photosynthesis that people and animals need to breathe?
5. How do the roots of trees protect the soil?

Answer key for teachers

1. An essay that explains a topic clearly with facts, reasons and examples.
2. Introduction, body and conclusion.
3. Photosynthesis.
4. Oxygen.
5. They hold the soil in place and reduce erosion during floods.

Assignment

Read the article again and list five main points about the benefits of trees. Use your list to write an expository essay of about 200 words with an introduction, body paragraphs and a conclusion.

Marking guide: the essay has the three parts, one main point in each body paragraph, facts or examples from the article, and correct spelling and punctuation.