Outside plant (large)

Question

I just noticed two leaves that have a large spot growing on them. The spots look more white than brown and it just started developing two days ago. Help
Unable to send photo

Answer 1

A white powdery appearance on leaves is usually caused by powdery mildew fungus:
https://www.gardeningknowhow.com/plant-problems/disease/get-the-cure-for-powdery-mildew.htm

If the spots later turn brown, it is most likely something else. What it is would depend on what plant it's growing on and the particular appearance of the spots.