 doubt
Dear teachers,
I was taught that doubt should be followed by 'whether/if' clause in declarative sentences and it should be followed by 'that' clause if it is an interrogative or negative sentence. But I found the following two sentences in Cambridge dictionary:
1. I doubt whether/if I can finish the work on time. (This is correc according to the grammatical rule).
2. [+ that] They had begun to doubt that it could be completed in time.
This is a declarative sentence but it is followed by 'that' clause. Could you please explain why?
Looking forward to hearing from you.
Thank you in advance.
Jiang |