Corrected sentence: Some caves are small, while others are huge, housing underground lakes, winding passages, and vast chambers.
Simple version for a 6-year-old: Some caves are small. Others are very big and have lakes, twisty tunnels, and big rooms.
Why this is better (easy steps):
- Start with a capital letter: "Some" not "some".
- Use "others" so you don't repeat the word "some."
- Put a comma before "housing" to join the ideas smoothly.
- Use commas between items in a list (lakes, winding passages, and vast chambers) and a period at the end.
- "Chambers" (or "big rooms") is a simpler word than "compartments" for caves.
Meaning of tricky words: "housing" means "having inside," "winding passages" are "twisty tunnels," and "vast" means "very big."