Cause and Effect — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. The car would not start because the battery was dead.
A car needs power from its battery to start the engine. The word 'because' shows that the dead battery is the reason the car would not turn on.
2. The cat knocked the cup off the table, so juice spilled everywhere.
The word 'so' connects the cat's action to its messy outcome. A cup falling off a table will tip over and spill whatever was inside.
3. Since the sidewalk was covered in ice, we walked on the grass instead.
'Since' opens the sentence and is capitalized as the first word. Icy sidewalks are slippery and unsafe, so the grass was a smarter choice.
4. He forgot to set his alarm. Therefore, he overslept and missed the bus.
'Therefore' joins two complete sentences and points to the chain of effects. Without an alarm, he could not wake up on time, so he missed the bus.
5. The children laughed because the clown made funny faces.
Funny faces are silly and make people giggle. The word 'because' shows the clown's actions are the cause of the children's laughter.
6. It was getting dark outside, so Dad turned on the porch light.
The word 'so' tells us the action that followed. Darkness made it harder to see, which is why Dad switched on the porch light.
7. Since the soup was too hot, she blew on it before taking a bite.
Blowing on hot food cools it down by adding cooler air. 'Since' starts the sentence and explains why she blew on her soup first.
8. They saved money all year. As a result, they could afford the family vacation.
'As a result' is a phrase that points to the outcome of an action. A whole year of saving added up to enough money for the trip.
9. The roof had a leak, so a puddle formed on the kitchen floor.
Water from a leaky roof drips down and collects below. The word 'so' shows that the puddle is the direct effect of the roof leak.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
The girl did not eat breakfast.
→ Her stomach growled during class.
The plant grew tall and green.
Heavy snow fell overnight.
→ School was canceled for the day.
It popped with a loud bang.
The balloon was filled with too much air.
→ It popped with a loud bang.
School was canceled for the day.
He watered the plant every day.
→ The plant grew tall and green.
Her stomach growled during class.
Each effect follows directly from its cause: an empty stomach growls, deep snow makes roads unsafe so school closes, too much air bursts a balloon, and steady watering helps a plant thrive.