(1) first 意为“先”“首先”，主要用来说明顺序，暗示接下去还有其他的动作或事件要发生，因此其后往往接有或暗示有 then, next, last 之类的词。如：
First think and then speak. 先想后说。
First, I must apologize to you. 首先，我要向你们表示歉意。
(2) at first 意为“起初”“开始”，它主要强调前后对照，暗示接下去的动作与前面的动词不同甚至相反，因此其后通常有but, afterwards, soon, at last 等词语相呼应。如：
The work was hard at first, but I got used to it. 起初这活儿很累，不过后来我习惯了。
At first they were very happy, but then things started going wrong. 起初他们生活得很幸福，但后来就开始出问题了。
单词：at first的近义词、反义词、形近词辨析
first/at first
Let's see who gets there first.咱们看看谁先到哪？
At first she was asleep.起初她睡着了。
<辨析>first 用作副词，意为“第一次”，“首先”。如：
I'll have to turn the wallet in first.我得先上交钱夹。
He was only a child when I first saw him.我第一次看见他的时候，他还是个孩子。
at first 与 at the beginning 同义，是“起初”的意思。如：
Are you interested in physics?Yes,but I wasn't at first.你对物理感兴趣吗？是的，但起初我并不感兴趣。
与单词：at first 相关的例句或者名人名言
I'm fascinated by that antique at first sight!
我第一眼就被这个文物吸引了！
I took against him at first sight.
第一次见面我就讨厌他了。
I had seen something of this imbroglio at first hand.
我曾经亲眼看到过这种乱七八糟的东西。
Since this often happens, I was not at first alarmed.
因为这事常发生，开始我没有警觉。
※If at first you don't succeed, try, try again. 初试不成功，努力勿懈怠。
※Judge not of men and things at first sight. 审人论事宜谨慎，一见之下莫断定。
※He was a bold man that first ate on oyster. 第一个吃牡蛎的人是勇士。
※If at first you don't succeed, try,try,try again. 再接再厉,终会成功.
