【英语时差8,16】聪明伶俐；聪明机智

If you have ever sat on a tack¹ by mistake, you'll know that tacks² are very sharp. Used correctly, they are quite useful for posting notices on bulletin boards, for example.

However, if touched incorrectly, their sharpness can hurt you.

When we say that a person is "as sharp as a tack," we are admiring their wit and perception. That person, we are saying, is not only intelligent, but is able to make clever comments about most things in an insightful way. If such a clever person becomes arrogant³ or sarcastic⁴, however, their words can hurt you.

1 tack   

n.大头钉；假缝，粗缝

参考例句：

• He is hammering a tack into the wall to hang a picture.他正往墙上钉一枚平头钉用来挂画。
• We are going to tack the map on the wall.我们打算把这张地图钉在墙上。

2 tacks   

大头钉( tack的名词复数 )； 平头钉； 航向； 方法

参考例句：

• Never mind the side issues, let's get down to brass tacks and thrash out a basic agreement. 别管枝节问题，让我们讨论问题的实质，以求得基本一致。
• Get down to the brass tacks,and quit talking round the subject. 谈实质问题吧，别兜圈子了。

3 arrogant   

adj.傲慢的，自大的

参考例句：

• You've got to get rid of your arrogant ways.你这骄傲劲儿得好好改改。
• People are waking up that he is arrogant.人们开始认识到他很傲慢。

4 sarcastic   

adj.讥讽的，讽刺的，嘲弄的

参考例句：

• I squashed him with a sarcastic remark.我说了一句讽刺的话把他给镇住了。
• She poked fun at people's shortcomings with sarcastic remarks.她冷嘲热讽地拿别人的缺点开玩笑。