Serve

The former has over 100 million results in Google; the latter has zero!

Anything other than the number of hits? Or the number of speakers?

Well, yes. We don't say the second.

I asked for a legitimate reason.

The 2nd version is not meaningless. Do they mean exactly the same?

soheil1I asked for a legitimate reason.The 2nd version is not meaningless. Do they mean exactly the same?

No.We do not say the second. 'HAVE the role of an example' is not natural English.

The fact that nobody says it is one reason nobody else says it.

soheil1I asked for a legitimate reason.

Actually, you asked for the difference between an expression that is commonly used and an expression that nobody uses. That difference in usage is the most obvious difference anyone could point out. There's nothing illegitimate about that. Attempting to see some subtle shade of meaning in an unused expression is wastin

So how to see the meaning?

I always wondered why they don't simply say "they are examples"

You can simply say "this is an example of…" "they are examples of…"

However, much of the beauty of the English - and any other - language stems from the many options offered by the language to achieve stylistic elegance.

As for the original question, it has been answered by the forum's vets. There is no meaning. "To have the role of an example" - this kind of formulation

Without further context the difference is the following.

"They serve as an example of good citizenship." = They are models of good citizenship.

"They have the role of an example of good citizenship." (This suggests that they have merely been assigned to play the role of good citizens.)

Xerxesforum's vets.

I understand that 'vet' in North American English is short for 'veteran' In British English it is short for 'veterinary surgeon'.