first(ly)
1.除了在逐项分别说明的时候以外，不可用firstly，如下面各句里的first不可改作firstly：
- I saw her first last Monday.
- He first asked my name.
- I have to post the letter first.
在逐项分别说明的场合，也有人用first而不用firstly，如First(ly), Lily had no clothes; secondly, she had no home; thirdly, she had no friends。Lastly也是这样。
2.A boy and a girl came in to tell me a story, the boy was the first to speak里的was the first to speak是“第一个讲”。A boy and a girl came in to tell me a story, the boy spoke first里的spoke first也是“第一个讲”。但The boy spoke first and then wrote down what he said是“那男孩先讲话，然后把他讲的话写下来。”I saw her first yesterday可能有三个意思：1.“我昨天第一次见她。”2.“我昨天第一个见她（我见了她以后才有别人见她）。”3.“我昨天先见她（然后见别人）。”
3.I am going to catch the first train back to Beijing里的first可以改作next。first是“（现在以后的）第一个”，就是“下一个”。
4.the first two, the first three等比the two first, the three first等普通，也合理。
5.the first thing或first thing是习语，用作状语短语，作“作为最先做的一件事”解。例如：I will answer his letter (the) first thing tomorrow morning.
6.at first=at the beginning, from the first=from the beginning, at the first不及at first普通。参见beginning 1
7.at first glance（最初看到时），at first hand（直接地）和at first sight（乍一看、一见之下）各种表达方式里都没有the。
