455. Fruit
(X) We didn't have many fruits this summer.
(O) We didn't have much fruit this summer.
Note: We rarely use the "plural form fruits" which means "different kinds of fruit".
Cyprus produces oranges, apricots, and other fruits.
456. Grass
(X) The dog lay down on the grasses.
(O) The dog lay down on the grass.
457. Dozen
(X) I want to buy three dozens eggs.
(O) I want to buy three dozen eggs.
Note: a dozen = 12 / a dozen + ~s = 12 ~s / a dozen eggs = 12 eggs
I'd like to buy a dozen eggs[two dozen eggs, three dozen eggs, etc].
When the word "dozen" isn't preceded by a "numeral" (like three) or by "a" we use the plural form.
There were dozens of eggs. "vs" There were three dozen eggs.