用于現(xiàn)在完成時的句型
1)It is the first/second time…. that…結(jié)構(gòu)中的從句部分，用現(xiàn)在完成時。
It is the first time that I have visited the city.
It was the third time that the boy had been late.
2)This is the… that…結(jié)構(gòu)，that 從句要用現(xiàn)在完成時.
This is the best film that I've (ever) seen.
這是我看過的最好的電影。
This is the first time (that) I've heard him sing.　這是我第一次聽他唱歌。

典型例題
(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 后面所加從句應(yīng)為現(xiàn)在完成時，故選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意為曾經(jīng)或無論何時，反意詞為never，此兩詞常用于完成時。This is the largest fish I have ever seen. It is/was the first time +that-clause 的句型中，從句要用完成時。

注意：非延續(xù)性動詞的否定形式可以與表示延續(xù)時間的狀語連用。即動作不發(fā)生的狀態(tài)是可以持續(xù)的。
(錯)I have received his letter for a month.
(對)I haven't received his letter for almost a month.