高中英语语法详解 Part 5 同义单词辨析 讲义-2026届高三英语上学期一轮复习专项

01 ago vs. before  

01 语法使用错误范例  

 Sample of Wrong Grammar  

A: Kate, come here quickly. This is your favorite TV show. I'm sure you don't want to miss it.

凯特，快过来。这是你最喜欢的电视节目，我想你一定不想错过。

B: Never mind. I have watched it two days before.

无所谓啦，我两天前就看过了。

02 语法误用详细解析  

 Grammar Analysis  

ago和before都可用来表示“在……（时间）之前”，但两者的内涵及用法都有相当明显的区別，请见以下说明：

（1-1）ago用来表示从现在起到过去的某一个“时间点”，通常与“过去时”连用，不与完成时连用，并且不可单独使用，必须搭配时间副词。例如：

This accident just happened 5 minutes ago.（这场意外就发生在五分钟之前。）

一般过去时＋ago→表示过去单一时间点

（1-2）当ago可与过去完成时连用时，目的则是用来加强语气或希望使语气更生动，表示“早已经”的意思。例如：

I haven't seen you since 3 years ago.（我自从三年前就没见过你了。）

过去完成时＋ago→强调语气

（2-1）before则是表示从过去某一个时间点往前推算，或者泛指过去（没有搭配明确的时间点），通常与“过去完成时”或“未来完成时”连用。例如：

Tommy said that he has already finished his project 2 days before.

（汤米说他两天前就已经完成了这个项目。）→从过去（两天前）往前推算。

（2-2）若是事件发生在过去，但没有特定的时间点，则可单独使用before，不需连接时间副词，用来泛指（过去╱从前）的时态，例如：

Have I met you before?（我以前见过你吗？）→泛指以前，没有特定时间点。

03 语法使用误用辨析  

 Grammar Error vs. Correct  

01．你以前看过熊猫吗？

x Have you ever seen a panda ago?

o Have you ever seen a panda before?

02．佩妮会在十点之前回来。

x Penny will come back ten o'clock ago.

o Penny will come back before ten o'clock.

03．埃琳娜说她跟丹尼五年前就已经结婚了。

x Elena said that she had married Danny five years ago.

o Elena said that she had married Danny five years before.

04．自从15年前，布朗先生就已经在这所学校教英语了。

x Mr. Brown taught English in this school since fifteen years ago.

o Mr. Brown has taught English in this school since fifteen years ago.

05．玛丽的奶奶三年前就去世了。

x Mary's grandma died three years before.

o Mary's grandma died three years ago.

06．其实我很早以前就认识那个人了。

x Actually, I have known that man long time before.

o Actually, I have known that man long time ago.

04 语法陷阱辨析练习  

 Grammar Practice  

请选出正确的选项。

01．He asked me whether I had been to Paris_______.

A ago