Today’s tour group was a busload of Indian physicians, who mostly had good English skills. But one kept having a lot of trouble with my description of Lake Michigan as “fresh water.”
“Where does the water come from?” he wanted to know. Originally from melting glaciers at the end of the last ice age, and replenished by precipitation within the watershed, I explained. “Oh, that is soft water, not fresh water,” he kept saying.
Is this some distinction in British English that I should know?
Strictly speaking, soft water is water with a low content in those cations which deposit as carbonates (the most common one is calcium, thus it is the one that gets mentioned in every ad for water softening products and machinery).