11.11 用于现在完成时的句型

　　1)It is the first / second time.... that…结构中的从句部分，用现在完成时。例如：

　　It is the first time that I have visited the city. 这是我第一次访问这城市。

　　This is the first time (that) I've heard him sing. 这是我第一次听他唱歌。

　　注意：It was the third time that the boy had been late.

　　2)This is +形容词最高级+that…结构，that 从句要用现在完成时。例如：

　　This is the best film that I've (ever) seen. 这是我看过的最好的电影。

　　典型例题

　　(1) ---Do you know our town at all? ---No, this is the first time I ___ here.

　　A. was B. have been C. came D. am coming

　　答案B. This is the first time 后面所加从句应为现在完成时，故选B。

　　(2) ---Have you ____ been to our town before? ---No, it's the first time I ___ here.

　　A. even, come B. even, have come C. ever, come D. ever, have come

　　答案D. ever意为曾经或无论何时，反意词为never，此两词常用于完成时。

　　注意：非延续性动词的否定形式可以与表示延续时间的状语连用。即动作不发生的状态是可以持续的。

　　(错)I have received his letter for a month.

　　(对)I haven't received his letter for almost a month.

　　11.12 比较since和for

　　Since 用来说明动作起始时间，for用来说明动作延续时间长度。例如：

　　I have lived here for more than twenty years.我住在这儿二十多年了。

　　I have lived here since I was born. 我从出生起就住在这儿了。

　　注意：并非有for 作为时间状语的句子都用现在完成时。

　　I worked here for more than twenty years. (我现在已不在这里工作。)

　　I have worked here for many years.(现在我仍在这里工作。)

　　注意：用句型转换的方法，很容易排除非延续动词在有for/since结构的完成时中的误用。

　　1)(对) Tom has studied Russian for three years. = Tom began to study Russian three years ago, and is still studying it now.

　　2)(错) Harry has got married for six years. = Harry began to get married six years ago, and is still getting married now.

　　显然，第二句不对，它应改为 Harry got married six years ago. 或 Harry has been married for six years.