What is the grammatically correct sentence?
- That's nice of you to say so!
- It's nice of you to say so!
I've come across 1 many times, but I feel it seems not to be grammatically correct, strictly speaking as "that" cannot be used as a dummy pronoun, so it should be written as 2 as "it" can work as a dummy pronoun referring to "to say so".
If you think of 1 as natural, could you tell me why?
Best Answer
To better analyze both forms, you can replace "so" with "that," as the two of them function the same grammatically in this context. (For the purpose of organization, we will place our analysis in curly braces.) Now, the sentences become:
{Clearly, only the second sentence works in the context of proper English grammar, the first one being redundant. In order for the first sentence to make sense, you would have to get rid of "that."}
Now, in order to obtain the answer to your question, change "that" back to "so," and because both "so" and "that" are grammatically equivalent, our analysis will be the same, except all occurrences of "that" replaced with "so."
Finally, this answers your question:
{Clearly, only the second sentence works in the context of proper English grammar, the first one being redundant. In order for the first sentence to make sense, you would have to get rid of "so."}