定冠词和不定冠词的主要用法区别
1.There is a rabbit under the tree.The rabbit is eating a carrot.第一次提到某物,用不定冠词,再次提到相同的事物,用定冠词
2.Who is your best friend in the company?虽然第一次提到,但是说话双方都知道的那个company.
3.Bill Gates is the richest man in the world.形容词或副词最高级前一定要用the.如果a,an和最高级连用,意思就变了：Bill Gates is a richest man in the world.比尔盖茨是世界上最有钱的人之一.
表示某一类事物时,可以用定冠词,不定冠词和复数三种形式表达 比如：The elephant is a friendly animal.An elephant is a friendly animal.Elephants are a friendly animal.注意：单数可数名词前一定要用冠词,无论名词前有多少修饰语 比如：My mother is a kind,generous,optimistic,open-minded,and honest person