一粒沙子的英文：
a grain of sand; a piece of grit

参考例句：

There is a grain of sand in his eye.
他眼里有一粒沙子。

There is a grain of sand in his eye.
他眼里有一粒沙子。

A grain of sand made my right eye tear.
一粒沙子弄得我右眼淌泪。

grain是什么意思：
n. 谷物；颗粒；一点儿；纹理；本质
v. 使成粒状

They are similar in grain.
他们气质相似。

Slowly each grain of wood was replaced with grains of minerals.
慢慢地所有的木质都被矿物微粒所取代。

Grain by grain and hen fills her belly
一粒一粒啄米,母鸡填饱肚皮

sand是什么意思：
n. 沙；沙滩
v. 用砂纸磨光；撒沙于；被沙堵塞

They panned off the sand and dirt.
他们用淘金盘淘去砂泥。

Sift gold from sand.
沙里掏金。

Sand castle damages easily.
沙堡容易受到损坏。

piece是什么意思：
n. 片，段；件，个；篇；硬币
v. 修补；填补；拼凑，缝合
adj. 计件的

a piece of flesh
娘儿们|女人|人

A piece of cake
小事一桩

Then It'started to break into pieces. These pieces started to move apart.
然后它开始分为很多块。这些分开的板块开始移动，分开。