Cause & Effect — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. The sidewalk was icy because it froze overnight.
Because introduces the reason the sidewalk became icy; it links cause to effect.
2. Tara missed the bus, so she walked to school.
So signals the effect; walking was the result of missing the bus.
3. Since it was raining, the game was moved inside.
Since works like because; it introduces the cause at the start of a sentence.
4. The bread was stale because the bag was left open.
Because links stale bread to its cause: air from the open bag.
5. My brother felt happy, so he smiled all day.
So introduces the effect; smiling was the result of feeling happy.
6. Since the lights went out, we used flashlights.
Since states the cause first; flashlights are the effect.
7. The pond froze because the temperature dropped below zero.
Because gives the reason the pond froze, which is cold temperature.
8. I forgot my lunch, so Mom brought it to school.
So signals the effect; bringing lunch was the result of forgetting it.
9. Since the book was overdue, Sam returned it fast.
Since opens with the cause; returning it fast is the effect.
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 seeds got water and sun
→ The plants grew tall
The plants grew tall
The phone was not charged
→ It would not turn on
It would not turn on
The baby was very tired
→ She fell asleep quickly
She fell asleep quickly
The window was left open
→ Rain came into the room
Rain came into the room
Matching causes to effects builds the habit of pairing reasons with results using clues from each sentence.