an amount of通常與不可數(shù)、無生命的名詞連用.如：She spent a very large amount of money yesterday.她昨天花了好大一筆錢.
an amount of一般是指某個(gè)物體的的多少,一般用an large amount of等.the amount of一般是某個(gè)物體的具體的數(shù)量,后面一般加名詞.
a number of與an amount of的意思差不多,但一般后面加群體性的名詞,如:people.the number of也和the amount of差不多,也是后面一般加群體性名詞 都用is