Year 4 English: Explanations: causes and effects
Part of the Year 4 English writing non-fiction and editing chapter. Chapter overview · whole chapter on one page
Explanations: causes and effects
An explanation tells the reader how or why something happens. Many explanations use cause and effect. The cause is the reason something happens; the effect is what happens as a result. Connecting words show the link: because comes before a cause, while so, as a result and this means introduce an effect.
Read the explanation in the box, look at the chain of causes and effects, then answer the questions in exercise 12D.
Why do leaves change colour?
In spring and summer, most leaves are green. This is because they contain a green substance called chlorophyll, which helps the leaf use sunlight to make food.
In autumn, the days become shorter and the weather turns cooler. As a result, the tree makes less chlorophyll, so the green colour fades. The yellow and orange colours that were already in the leaf begin to show.
The tree then seals the base of each leaf stalk with a thin layer of cells. Because no water or food can pass through, the leaf dies and falls to the ground. This means the tree saves its energy for the winter.
Key ideas
- An explanation says how or why something happens.
- A cause is the reason; an effect is the result.
- Because introduces a cause, so and as a result introduce an effect.
- Technical words, such as chlorophyll, should be explained in the same sentence or the one after it.
- Write the effect first, then give the cause after because, or the other way round.
Method. Find the cause, then the result of the cause. The connective so links them.
- Find the connective. So links the cause to the result.so
- Find the cause. The days become shorter is the reason.The days become shorter
- Find the effect. The tree makes less chlorophyll is the result.the tree makes less chlorophyll
- Write the answer. the tree makes less chlorophyll
Check. The effect comes after so. ✓
Watch out. The effect is the result, so it comes after the connective so.
Method. Find the effect in paragraph 2, then the cause that comes before it.
- Find the words. The text says the green colour fades, so the yellow and orange colours begin to show.the green colour fades
- Find the cause. The green colour fades because the tree makes less chlorophyll.the tree makes less chlorophyll
- Say what this means. The fading green lets the other colours show.because the green colour fades
- Write the answer. because the green colour fades
Check. The fading green is the cause of the other colours showing. ✓
Method. Write the effect first, then give the cause after because.
- Write the effect. Leaves are green in summer is the thing to explain.Leaves are green in summer
- Add the cause after because. The cause is the chlorophyll that the leaf contains.because they contain chlorophyll
- Check the sentence. The cause follows because and explains the effect.Leaves are green in summer because they contain chlorophyll.
- Write the answer. Leaves are green in summer because they contain chlorophyll.
Check. The cause follows because, and explains the effect. ✓
Watch out
Watch out: a cause and an effect are not the same thing. The shorter days are the cause; the tree making less chlorophyll is the effect.
Exam tip
Grown-up tip. Ask your child to explain one thing they know, such as why a puddle dries up, using because. Then ask: "What happens next, and why?" to add an effect.
Exercise 12D Practice: explanations, causes and effects
Method. Find the detail that the text states.
- Find the words that answer the question. Scan the text for the detail the question asks about.the days become shorter and the weather turns cooler
- Check that the detail is stated, not guessed. The cause comes before the words As a result.the days become shorter and the weather turns cooler
- Write the answer. the days become shorter and the weather turns cooler
Check. The text states this detail. ✓
Method. Find the detail that the text states.
- Find the words that answer the question. Scan the text for the detail the question asks about.As a result, the tree makes less chlorophyll
- Check that the detail is stated, not guessed. As a result shows that the next sentence is an effect of the cooler weather.As a result
- Write the answer. As a result
Check. The text states this detail. ✓
Method. Test each choice against the text or the situation.
- Read what the question asks for. Decide what the text or the situation needs.
- Test the choice. Because introduces the reason that the leaf dies.Because fits
- Reject the other choices. Then and Finally show the order of events, not a reason.Then and Finally do not fit
- Write the answer. Because
Check. The choice fits the text or the situation. ✓
Method. Find the detail that the text states.
- Find the words that answer the question. Scan the text for the detail the question asks about.helps the leaf use sunlight to make food
- Check that the detail is stated, not guessed. The first paragraph says what chlorophyll helps the leaf do.use sunlight to make food
- Write the answer. use sunlight to make food
Check. The text states this detail. ✓
Method. Find the detail that the text states.
- Find the words that answer the question. Scan the text for the detail the question asks about.seals the base of each leaf stalk
- Check that the detail is stated, not guessed. The third paragraph describes what the tree does before the leaf falls.seals the base of each leaf stalk
- Write the answer. seals the base of each leaf stalk
Check. The text states this detail. ✓
- The leaves are green.
- The days are shorter, so the tree makes less chlorophyll.
- Autumn is a season.
Method. Test each choice against the text or the situation.
- Read what the question asks for. Decide what the text or the situation needs.
- Test the choice. It joins a cause, the shorter days, to an effect, less chlorophyll, with so.The days are shorter, so the tree makes less chlorophyll. fits
- Reject the other choices. The other two sentences state facts, but they do not give a cause and an effect.The leaves are green. and Autumn is a season. do not fit
- Write the answer. The days are shorter, so the tree makes less chlorophyll.
Check. The choice fits the text or the situation. ✓
Method. Think about what the green colour does to the other colours.
- Look at the second paragraph. The yellow and orange colours were already in the leaf.already in the leaf
- Link it to the green. When the green fades, the other colours are no longer hidden.no longer hidden
- Write the answer. they were already in the leaf, but the green colour covered them up.
Check. The other colours were there all along. ✓
Method. Write the effect first, then the cause after because.
- Write the effect. The effect is that leaves are green in summer.Leaves are green in summer
- Add the cause after because. Chlorophyll is the substance that makes them green.because they contain chlorophyll
- Write the answer. Leaves are green in summer because they contain chlorophyll.
Check. The cause is given after because. ✓
Method. Find the detail that the text states.
- Find the words that answer the question. Scan the text for the detail the question asks about.This means the tree saves its energy for the winter.
- Check that the detail is stated, not guessed. The last sentence says what the result of sealing the leaf is.saves its energy for the winter
- Write the answer. saves its energy for the winter
Check. The text states this detail. ✓
Method. Put the items in the order in which the text gives them.
- Find the first item in the order. The first step or idea comes first in the text.the days become shorter
- Fill in the rest in the same order. Each one follows on from the one before it.the tree makes less chlorophyll, the leaf dies and falls
- Write the answer. the days become shorter, the tree makes less chlorophyll, the leaf dies and falls
Check. The items follow the order of the text. ✓
Method. Find the word Because, then copy the cause that follows it.
- Find Because. The reason for the falling leaf follows the word Because.Because
- Copy the cause. The cause is that no water or food can pass through.no water or food can pass through
- Write the answer. no water or food can pass through.
Check. The cause is copied from the text. ✓