chalk的基本意思是指“制造白色或彩色粉笔的白垩”，表示一种物质，是不可数名词。作“粉笔”讲时，一般用作不可数名词，但说“各种颜色的粉笔”时，则要用复数。表示“一支粉笔”时用a piece of chalk，“两支粉笔”用two pieces of chalk。
1.He chalked the message on the blackboard.他用粉笔将消息写在黑板上。
2.The two places， he insists， are as different as chalk and cheese.他坚持说那两个地方有天壤之别。
3.There was a blackboard with seven names chalked on it.黑板上用粉笔写着7个人名。
4.We shall chalk up his good points.我们将记下他的优点。
5.The teacher wrote with a stick of chalk.老师用粉笔写字。
