grammaticality - Using an appropriate article before the word "leadership"

I had a quick question. Recently a co-worker posted a how-to guide entitled "How to be a good leadership at work". To me the sentence seems incorrect. But I can't explain why. Technically leadership is a noun, just like in the sentence "How to be a good person at work" would be correct, because person is also a noun.

Perhaps it's one of those things that sounds incorrect to me but really is correct. Can anyone explain this to me?

Answer

The problem is with the verb not the noun. So, while you can be a good person or a good leader, you cannot be a good leadership. Similarly, you can be a good friend but not be a good friendship. The sentence can be rewritten as:

• How to be a good leader at work.

or

• How to demonstrate good leadership at work.