【解答】在普通的字典上interest 一字作名词或动词用，甚至变成过去分词作形容词用，后面都是加介词的“in”再接名词或动名词的。

例如：He has no interest in such matters. (他对这种事没有兴趣。)

I do not interest myself in politics. (我对政治不感兴趣。)

He is interested in studying Americas English. (他对研究美国英语很感兴趣。）

但在be interested in doing 一种常见的用法之外，还有be interested to do一种常见的用法，二者之间，存在微妙的差别。前者表现在性质上或习惯上常常具有这种兴趣的抽象的含义，面后者则是说到从此即将付诸实行的具体的行为。例如：

(a) He is interested in buying this gramophone record.

(b) He is interested to buy this gramophone record.

(a)句的意思是“他常对购买这张唱片感到兴趣”，比方说贝多芬的月光曲吧，不问是谁弹的，只要他遇到是月光曲的唱片他就要买，他都有购买的兴趣。这对于他成为一种习惯的行为了。至于（b）句的意思则为“他对购买这张唱片很感兴趣”，或是“他很想要买这张唱片”(=He is inclined to buy this gramophone record.)

这种接不定词的用法，虽很少见，但并不新奇，这在十八世纪英国历史家Edward Gibbon(（1737-94）著《罗马兴亡史》

（The Decline and Fall of the Roman Empire)就写得有:

The emperor himself was interested not to deface the splendor of his own cities. (皇帝本人都很当心不要级坏了他自己的那些城市的壮丽。)

晚年定居在美国的英国小说家James Hilton (1900-54)，在Time and Time Again 一书中也写得有：

Anderson said he thought she knew it was something we'd be interested to hear. (安得生说，他以为她知道这是一件我们高兴听到的事。)

在英国小说家Evelyn Waugh (1903-66)在Decline and Fall 一书中也有这样的句子：

I shall be interested to hear what your experience has been over the matter. (我很想听到关于这件事情的你的经验。)

美国的大作家Theodore Dreiser (1871-1945)在Albertine 一作中也有：

But having seen her again I was interested to learn of the state after these several years. (但在再见到她以后，我变得很想知道这些年来的情况。）还有在Lofting 写的The Voyage

Doctor Doolittle一书上也发现有下列的文句：

I was tremendously interested to see how a ship could steered into a port at night with nothing but light-houses and a compass to guide you. (我非常想要看看一条船怎样能在黑只凭灯塔的光和罗盘针的指示而驾驶进入海港的。)