冠词“类别”的区别

题目

冠词“类别”的区别
a/an/the+单数可数名词 这是可以互换吗?但又有什么差别?例：what's this in English?----It's (a) ruler 这句话可以用the+单数可数名词吗?It's said that (the) umbrella was invented over four thousand years ago ba Chinese people.这句话可以用a/an+单数可数名词吗?

答案

你的第一个例子不能用定冠词 因为它是泛指 .泛指同类东西中的任意一个.虽然定冠词也可表类别 ,但在这里不行.因为它说明的是 this.下面句子可以 a horse is a useful animal.the horse is a useful animal.horse are ...