"a grain of sand"
"a grain of sugar"
"wheat is a grain that is grown in Kansas"
"there was a grain of truth in what he said"
"he does not have a grain of sense"
"saw the board across the grain"
"breadfruit has the same texture as bread"
"sand of a fine grain"
"fish with a delicate flavor and texture"
"a stone of coarse grain"
"His hands were grained with dirt"