"What amazing lightning!"
Translation:איזה ברק מדהים!
Probably my misunderstanding, but I was expecting to see: איזה ברקים מדהים
Is איזה ברק מדהים as written something like "What an amazing lightning bolt"?
Are you asking because מדהים ends with ים? Or because "lightning" is general rather than a single lightning bolt? "What an amazing lightning bolt" is a good translation in my opinion. מדהים (if that's what you're asking) ends with ים because it comes from the root דהם, its plural form would be מדהימים.