Let's look at the sentence together:
A nice cozy hole is a perfect hiding place for a sly fox.
We can split it into small bits and name each bit:
- A — means one. (Like one toy.)
- nice and cozy — describing words. They tell us what the hole is like.
- hole — the thing. This is a noun (a name for a thing).
- is — a little joining word that tells what the hole is. (We call it a verb, a linking verb.)
- a — again, means one.
- perfect and hiding — more describing words. They tell us about the place.
- place — another thing (a noun).
- for — shows who the place is for.
- a — one again.
- sly — a describing word that tells us about the fox (means sneaky).
- fox — the animal (a noun).
Short and simple: The sentence says that one nice, cozy hole is a very good hiding spot for one sneaky fox.
Fun little activity: Point to the word hole and say "hole is a thing." Then point to cozy and say "cozy tells us more about the hole." Finally point to fox and say "fox is the animal." Try saying the whole sentence out loud!