"This big, blue butterfly is absolutely magnificent."
Translation:Ce grand papillon bleu est absolument magnifique.
Thank you! I've been tootling along trying to figure out which sounded right, as a rule. I knew gros was used for the size of things in the context of grossir, and grand was for things like buildings, and for the most part, it works. But I'd not seen a simple explanation until now. Much appreciated!