What plurals are spelt incorrectly and the correct spelling (plural)

Answer:
1. Incorrect. It has to be puppies.
2. Correct.
3. Correct.
4. Incorrect. It has to be tomatoes.
5. Correct.
6. Incorrect. It has to be geese.
7. Incorrect. It has to be pianos.
8. Correct.
9. Incorrect. It has to be sheep.
10. Correct.
11. Correct.
12. Incorrect. It has to be leaves.
Explanation:
I'm going from left to right.