形容词careful 与careless的搭配与用法

1. 表示某人做某事很粗心，通常用于it is careless of sb do sth。如：

It was careless of you to leave your camera in the taxi. 你把照相机留在计程车里实在太不小心了。

该句式也可换成以“人”作主语的句子。如：

你犯这样的错误真是粗心。

It was careless of you to make such a mistake.

=You were careless to make such a mistake.

注意，这样用时句首的it为形式主语，不能改为 that。但是这类句子后面不出现不定式，那么句首的it也可换为 that。如：

It was very careless of him.=That’s very careless of him. 他太粗心了。

2. 比较be careless to do sth与be careless in doing sth：前者中的不定式为结果状语，指由于粗心而做了某事；后者中的in doing sth表示时间，其中的in相当于while，指在做某事时很粗心。如：

He was careless to make the mistake. 他很粗心，结果出了错。

He was careless in typing the letter. 他打这封信时很粗心。

3. 表示“对……不在意或不关心”等，其后可接介词 about, of, with 等。如：

He’s careless of [about] his speech. 他讲话随便。

She is careless of [with] his health. 她不注意身体。

He is careless with his pronunciation. 他对语音不注意。

Don’t be so careless with your money. 你花钱不要这样随便。