Iron is more useful than any other metal ( Change into positive degree)?

Iron is a useful metal.

Positive is the simplest form of statement using the given adjective that is neither comparative or superlative.

Consider: fast, faster and fastest. Fast is the positive form.

You get irregular forms eg Good, better, best or in your case:

Useful, more useful, most useful.

Iron is a useful metal.

The positive degree makes only commentary on the noun at hand; it makes no comparison of better than or worse than anything else.

EDIT - Oy, you people are so childish:

Positive Degree :

Examples :

Mohan is a tall boy.

India is as powerful as China.

She is beautiful girl.

They are late today.

His marks are low.

Her walk is slow.

They are as week as my father.

The train runs fast.

He is rich.