Here are three easy ways to say the same idea:
- Frogs lay eggs in water. The eggs hatch into tadpoles, and when the tadpoles become adult frogs they live on land.
- Frogs lay their eggs in ponds or puddles. The eggs turn into tadpoles, and later the tadpoles change into frogs that go onto land.
- Eggs from frogs hatch in water into tadpoles. After the tadpoles grow up into adult frogs, they live mostly on land.
Short summary: eggs in water → tadpoles → grown-up frogs on land.