新概念英语第二册 Lesson 4 · 语法精读与固定搭配分类
本课是「弟弟在澳大利亚的旅行来信」，语法主线是 现在完成时（have / has + 过去分词）配 just / already / never / before / for，并对照 现在进行时与 一般将来时 will。
| 句子 | 语法点 |
|---|---|
| I have just received a letter from my brother, Tim. | 现在完成时 have + 过去分词（receive → received）· just 插在 have 与分词之间，表示「刚刚」· a letter from sb = 某人来的信 |
| He is in Australia. | 一般现在时陈述当前状态 · Australia 前不加 the |
| He has been there for six months. | 现在完成时 have been + for + 时间段，表示「已经持续了多久」· be 的过去分词是 been |
| Tim is an engineer. | 职业前加 a / an（engineer 以元音音素开头，用 an） |
| 句子 | 语法点 |
|---|---|
| He is working for a big firm and he has already visited a great number of different places in Australia. | 现在进行时 表示现阶段正在进行（并非此刻）· already 放 has 与过去分词之间 · a great number of + 可数名词复数 = 许多 |
| He has just bought an Australian car and has gone to Alice Springs, a small town in the centre of Australia. | 两个现在完成时并列（has bought / has gone）· Alice Springs 是同位语，解释前面的地名 · in the centre of = 在…中部 |
| He will soon visit Darwin. | 一般将来时 will + 动词原形 · soon 表示「不久」 |
| From there, he will fly to Perth. | from there = 从那里 · fly to + 地点 = 飞往 |
| 句子 | 语法点 |
|---|---|
| My brother has never been abroad before, so he is finding this trip very exciting. | never 插在 has 与 been 之间 · before 放句末，与 never 呼应表示「从未」· exciting 修饰物（令人兴奋的）· is finding 是现在进行时 |
| 短语 | 用法与例句 |
|---|---|
| a letter from sb | 某人寄来的信；回信是 a letter to sb |
| for six months | 与现在完成时连用，表示持续的时间；since 后接时间点 |
| work for a firm | 在某个公司工作；work for 后接雇主或公司 |
| a great number of | 许多（后接可数名词复数）；a great deal of 后接不可数名词 |
| go to Alice Springs | 去某地；地名后不加 the，但 the United States 这类例外 |
| be abroad | 在国外；abroad 是副词，前面不加 to（✗ go to abroad） |
四个信号词 just（刚刚）、already（已经）、never（从未）、before（以前）都放句子里配合现在完成时，看到它们就要想到 have / has + 过去分词。