Is reform a common word​

Yes. It is a common word used if that's what you mean... There's

Police reform

or you could say

This constitutional reform was severely criticized by contemporary political experts.

It is a common word used...

Explanation:

Yes, but that does not mean it is used often. It has a use that no other word will fully do and sooner or later everyone comes across the word. For example a business will reform the way its salespeople will try and make a product familiar to a customer.

They will reform their previous methods.

A reform school is meant to change someone's behavior.

hi,   i believe the outlines that were supposed to be showing at the sentences, are not. could you highlight them somehow?