“Mr. Derbyshire—For years I have wondered whether the noun referring to my

favorite breakfast food–grits–is singular or plural. (‘Grits is good for

you’ vs. ‘Grits are good for you.’) Now you may have provided me with the

solution. Is ‘grits’ in fact aggregative? Same for ’suds’? Or does the ’s’

at the end of these nouns make them plurals? One could argue, I suppose,

that ‘grits’ is just the plural of ‘grit’ (though you’d have a hard time

separating a single ‘grit’ from a bowl of them). But is it really possible

to isolate a single ’sud’?”

Thank you, Sir. I live but to serve.

These are deep matters we are opening up here, though. For example:

English has an historical tendency to turn nouns of the aggregative type

(sand, rice, grass, paper, water) into ordinary singular/plural nouns when

it can get away with it. This especially happens when the aggregative noun

has the misfortune to end in an “s” or “z” sound, making it *sound* like a

plural. Then a new word emerges, and you no longer have to say “a grain

of…” or “a blade of…”

This happened with “pease,” once a simple aggregative. Until (I think — I

am away from my reference books) the 18th century, there was no such thing

as a pea. I believe the same thing happened with “cherry.”