如何区别if 和when引导的状语从句 if和when引导条件状语从句区别？

if\u548cwhen\u5f15\u5bfc\u6761\u4ef6\u72b6\u8bed\u4ece\u53e5\u533a\u522b

when\u4e0eif\u7684\u533a\u522b\u4e3a\uff1a\u610f\u601d\u4e0d\u540c\u3001\u7528\u6cd5\u4e0d\u540c\u3001\u4fa7\u91cd\u70b9\u4e0d\u540c\u3002
\u4e00\u3001\u610f\u601d\u4e0d\u540c
1\u3001when\uff1a\u4ec0\u4e48\u65f6\u5019\uff0c\u4f55\u65f6\u3002
2\u3001if\uff1a\u5982\u679c\uff0c\u5047\u82e5\u3002
\u4e8c\u3001\u7528\u6cd5\u4e0d\u540c
1\u3001when\uff1awhen\u7684\u57fa\u672c\u610f\u601d\u662f\u201c\u4ec0\u4e48\u65f6\u5019\u201d\u3002\u53ef\u7528\u4f5c\u7591\u95ee\u526f\u8bcd\uff0c\u7528\u6765\u8be2\u95ee\u67d0\u4e8b\u66fe\u53d1\u751f\u6216\u5c06\u8981\u53d1\u751f\u7684\u65f6\u95f4\uff0c\u5f15\u5bfc\u7279\u6b8a\u7591\u95ee\u53e5\uff0c\u8fd8\u53ef\u7528\u4f5c\u5173\u7cfb\u526f\u8bcd\u5f15\u5bfc\u9650\u5236\u6027\u5b9a\u8bed\u4ece\u53e5\u3001\u975e\u9650\u5236\u6027\u5b9a\u8bed\u4ece\u53e5\u548c\u8868\u8bed\u4ece\u53e5\uff0c\u8868\u793a\u201c\u662f\u2026\u65f6\u5019\u7684\u4e8b\u201d\u3002

2\u3001if\uff1aif\u4f5c\u4e3a\u4ece\u5c5e\u8fde\u8bcd\uff0c\u53ef\u5f15\u5bfc\u6761\u4ef6\u72b6\u8bed\u4ece\u53e5\u3001\u8ba9\u6b65\u72b6\u8bed\u4ece\u53e5\u548c\u540d\u8bcd\u4ece\u53e5\u3002if\u5f15\u5bfc\u6761\u4ef6\u72b6\u8bed\u4ece\u53e5\uff0c\u4ece\u53e5\u53ef\u4e3a\u771f\u5b9e\u6761\u4ef6\u4ece\u53e5\uff0c\u4e5f\u53ef\u4e3a\u865a\u62df\u6761\u4ef6\u4ece\u53e5\u3002\u5982\u4e3a\u771f\u5b9e\u6761\u4ef6\u4ece\u53e5\uff0c\u8c13\u8bed\u7528\u9648\u8ff0\u8bed\u6c14\uff0c\u8868\u793a\u53ef\u80fd\u6027\u5f88\u5927\uff0c\u4f5c\u201c\u5047\u4f7f\u201d\u201c\u5982\u679c\u201d\u89e3\uff0c\u901a\u5e38\u7528\u4e00\u822c\u73b0\u5728\u65f6\u4ee3\u66ff\u4e00\u822c\u5c06\u6765\u65f6\u3002
\u4e09\u3001\u4fa7\u91cd\u70b9\u4e0d\u540c
1\u3001when\uff1awhen\u5f15\u5bfc\u6761\u4ef6\u72b6\u8bed\u4ece\u53e5\u8bb2\u8ff0\u7684\u662f\u5ba2\u89c2\u60c5\u5f62\u3002
2\u3001if\uff1aif\u5f15\u5bfc\u7684\u5219\u662f\u5047\u8bbe\u6027\u7684\u6761\u4ef6\u72b6\u8bed\u4ece\u53e5\uff0c\u901a\u5e38\u9075\u5faa\uff1a\u201c\u4e3b\u5c06\u4ece\u73b0\u201d\uff0c\u5373\u4e3b\u53e5\u7528\u5c06\u6765\u65f6\uff0c\u4ece\u53e5\u7528\u4e00\u822c\u73b0\u5728\u65f6\u3002

if\u5f15\u5bfc\u6761\u4ef6\u72b6\u8bed\u4ece\u53e5\uff0c\u8868\u793a\u201c\u5982\u679c\u201d\u3002\u5982\u679c\u5047\u8bbe\u7684\u6761\u4ef6\u6210\u7acb\uff0c\u4e8b\u60c5\u5c31\u4f1a\u53d1\u751f\u3002when\u5f15\u5bfc\u65f6\u95f4\u72b6\u8bed\u4ece\u53e5\uff0c\u8868\u793a\u201c\u5f53...\u7684\u65f6\u5019\u201d\u3002
if
1\u3001(\u8868\u793a\u6761\u4ef6)\u5982\u679c
He will come if you invite him.
2\u3001(\u8868\u793a\u865a\u62df)\u5047\u5982,\u8981\u662f
If I were you,I would never do that.
3\u3001.(\u8868\u793a\u8ba9\u6b65)\u5373\u4f7f
We'll go even if it rains.
4\u3001\u662f\u5426
I wonder if she is ill.
5\u3001(\u8868\u793a\u56e0\u679c\u5173\u7cfb)\u6bcf\u4e00\u6b21...\u7684\u65f6\u5019(\u603b\u662f\u4f1a)
If I feel any doubt,I inquire.
6\u3001\u540d\u8bcd cn.\u6761\u4ef6;\u8bbe\u60f3
There are too many ifs in his offer.
when
7\u3001adv. \u4ec0\u4e48\u65f6\u5019\uff1b \uff08\u7528\u4e8e\u65f6\u95f4\u7684\u8868\u8fbe\u65b9\u5f0f\u4e4b\u540e\uff09\u5728\u90a3\u65f6\uff1b \u5176\u65f6\uff1b \u5f53\u65f6
When did you see him last?
8\u3001conj. \u5728\u2026\u65f6\uff1b \u65e2\u7136\uff1b \u5982\u679c\uff1b
We're not sure when the curfew is tonight.
9\u3001pron. \u4ec0\u4e48\u65f6\u5019\uff1b \u90a3\u65f6\uff1b
That was when I was eight.
10\u3001n. \u65f6\u95f4\uff0c\u65f6\u5019\uff1b \u65e5\u671f\uff1b \u573a\u5408\uff1b
This is not normal when expressing grief and sadness.

首先要知道if引导的是条件状语从句，而when引导的是时间状语从句。从语法角度是有严格区别的。当when引导的时间在将来时，通常可以和 if互换。从词义角度看，if是如果，偏向于虚拟语气，多用于对未来的假设或推测，when多用于一般描述或许诺，条件满足即发生。

if表如果. 多用虚拟语气. when是时间装语. " 当... 时"

扩展阅读：if when 引导的从句 ... if then引导的从句用法 ... 只能用whether不用if ... 初中阶段when和while ... when引导的三种时态 ... if和when主将从现区别 ... if和when可以替换吗 ... when 后面为啥doing ... when和if什么时候可以互换 ...