[1]It began to rain when I was watering the garden.
[2]It was very wise to leave when you did.
[3]I will leave when you do.
这三句，根据张满胜老师的说法，[2]中的when修饰leave, 而不是修饰主句，该句可以改写为To leave when youdid was very wise.
[1]则修饰主句，可以改写为When I was watering the garden, it began to rain.
对于这两种改写我都没疑问。
问题是，修饰主句这一说法的模糊性。若是修饰某一动词，以时间状语为例，还可以说明该动词发生的时间。
[问题]
1.那样修饰主句的意思是呢？表示"主句所代表的事件"发生的时间吗？主句所代表的事件发生了，也肯定涉及动词，所以时间状语最后还是落到动词发生的时间了。所以两种说法有什么区别只不过修饰什么动词吗？修饰主句的限定动词就是修饰主句吗？
2.第一句可否说修饰"began to rain"呢，状语从句表示开始下雨的时间。
3.第三句，张满胜老师的意思是修饰leave。我感觉[3]的意思是When you leave, Iwill leave to.这么说修饰主句也可以吧？
我感觉区别一个状语是谓体状语还是句子状语，只须是主句为否定句时，状语是不是在否定范围之内。假如时间状语是句子状语，则否定范围不包括状语，该状语放在句末和句首，一般意义不变。以下是夸克对时间状语的简短说明：
8.51
... ...
Time adjuncts are readily predicational when a verb lacks other complementation :
The guests arrived in the early evening.
I waited till14.30.
She is coming this afternoon.
But when there is alternative complementation, most types of time adjunct
just as readily assume a sentential function:
I waited patiently enough for an interview till 4.30.
Till 14.30, I waited patiently enough for an interview.
She is coming for a tutorial this afternoon.
In many cases, moving a sentential adjunct from E to I has no effect on
interpreting the scope of negation:
She isn't coming for a tutorial this afternoon.
This afternoon, she isn't coming for a tutorial.
We didn't speak to each other during the entire afternoon.
During the entire afternoon, we didn't speak to each other.
