A practical english grammar - Vyssaja skola 1978
Chapter 12 - VERB + THAT-clause
Sound symbols
In this construction, the subordinate verb is in the form in which it occurs in independent sentences. It always has a subject, and the subject is I, he, she, we', etc., rather than me, him, etc. The construction may be introduced by the connecting word that, or there may be no connecting word at all.
I know that he is here.
I know he is here.
I doubt that it will be possible.
We hope that you have a good time.
The characteristic verbs in this pattern mostly have to do with knowing, reporting, or discovering information; a few, like hope, express wishes or desires. Here is a list of common verbs used before that-clauses:
admit hope reply
agree imply report
believe infer say
boast insist see (= understand)
conclude judge show
discover know suppose
fear mean tell
feel (= be convinced) recall think (= be of the opinion)
hear (= be informed) remember
When insist is used in this pattern, the subordinate clause states something that (in the speaker’s view) is true. See also Pattern I4.I.
Tell must always be followed by an indirect object or a to-phrase in addition to the t/iat-clause. Say is never followed by an indirect object, but may be followed by a to-phrase; it may also be followed by the that-clause alone.
Tell him that I will wait for him.
Say that I will wait for him.
If the verb in the that-clause is be, the same idea can often be expressed by a noun + infinitive construction.
I believe that he is a good doctor.
I believe him to be a good doctor.
I discovered that the job was difficult.
I discovered the job to be difficult.