It would have been rude to ask the woman in Atlanta if she had a relative in Hong Kong who looked like her. That's why I thought better of it. The expression "think better of it" means to decide not to do something after realizing it is not a good idea. It is unclear how the expression "spitting image" originated. Some believe it is linked to the word "spit". They believe if you are the spitting image of someone then it is like you were formed by the spit of that person. A person, of course, cannot be formed by the spit of another person. It is just an expression to describe two people who look very much alike.
The expression "a chip off the old block" is similar to "spitting image" but it is used only to describe someone who looks like or has similar characteristics to his or her parents. If you look like your father or mother, people can say you are a chip off the old block. The expression is mostly used to describe a son who looks like or has similar characteristics to his father. The expression comes from a block of wood. The old block is the father. The chip, a small piece of wood, is the son. If you take a chip from the block, it will look like the block.
幾個星期前在佐治亞州的亞特蘭大，我見到一個亞裔女人，簡直跟一位我在香港認識的亞裔女士長得一模一樣（spitting image）。我本想跟她說她跟我認識的某人長得一模一樣（spitting image），但想想還是不要搭訕為好（thought better of it）。若你是 the "spitting image" of someone，意思即你跟某人長得一模一樣，又或跟那人相貌非常酷似。一個兒子可以跟他的父親長得像餅印一樣（spitting image），一個女兒亦可以跟母親長得像餅印一樣（spitting image）。除非某人跟另一個人有血緣關係，否則兩人要長得一模一樣（spitting image），是很罕見的。
要是我去詢問那位在亞特蘭大的女士，是否有一名跟她長得非常酷似的親戚在香港，那就不免顯得冒昧無禮了，因此我thought better of it。習語 "think better of it" 意即因為意識到某事並非好主意，而改變主意、決定不去做。至於習語 "spitting image"，來源則不大清楚，有些人相信它跟 "spit" 一字相關，認為若你是某人「吐口水的形象」（spitting image），那你就像是用那人的口水（spit）造出來的人。當然，一個人不可能是另一個人吐口水（spit）所造出來的，這只是一個習語，用來形容兩個人長得非常酷似。
習語 "a chip off the old block" 跟 "spitting image" 大同小異，但單單用來形容某人跟其父母長得很像，又或有很相近的特質。若你長得像你爸爸或媽媽，人們便可以說你是a chip off the old block。這個習語通常是用來形容子肖其父，兒子跟他的父親非常相像，又或擁有相近的特徵。這個習語來自一塊木頭，那個老木頭就是比喻父親，而那片木塊的碎屑就是比喻兒子；若你從一塊木頭上切下一塊木屑，那它看起來就很像那塊木頭。中譯：七刻
Michael Chugani 褚簡寧