I have two almost identical sentences but only the second one is correct: (THE SENTENCES ARE QUOTED FROM CAMBRIDGE GRAMMAR.)
- The snow which fell overnight has turned to ice. (not
The snow falling overnight has turned to ice.)
- The snow which fell overnight has caused traffic chaos. ( or The snow falling overnight has caused traffic chaos.)
Why is the first sentence incorrect?
I've done a little research to get the source of those two sentences. The book provides the following explanation for the examples you mentioned above: "Sometimes, however, you can't use an -ing clause. For example:
- When the event or action talked about in the defining relative clause comes before the event or action talked about in the rest of the sentence, except when the second event or action is the result of the first."
According to that explanation, I see that the second sentence is perfectly fine with its two forms.
- The snow which fell overnight has caused traffic chaos. = The snow falling overnight has caused traffic chaos. = The falling of snow has caused traffic chaos. (Cause and effect).
As for the first sentence, I think the writer means that you can't say 'the falling of snow (the first completed action) has turned it into ice', because it is illogical.