Indicating the speaker's intention
Verbs are usually used with the pattern V that in order to describe what someone else has said or thought. However, some verbs with this pattern are often used in the simple present tense with I or we as the Subject, as a preface to a statement, in order to indicate what kind of statement the speaker intends to make, for example a confession, a desire, or a promise.
I confess I'm sorry for her.
I insist that the funds be returned.
Except in the case of verbs concerned with statements or requests that something should be done, and the verb disagree, the Subject and verb can come after or within the clause. The word that is not used.
acknowledge admit advise agree ask beg bet concede confess confirm contend declare demand disagree guarantee insist maintain move pledge pray predict promise propose recommend submit suggest swear
This, I admit, is still an open question.
I'll come back for that, I promise.
Some verbs are used in this way with a modal: usually would, must, or could in a statement, and may, can, or could in a request.
add admit agree argue claim comment confess contend deny emphasize insist mention observe say state stress testify
May I just say that we appreciated the understanding and help of all those who felt for us in our misfortune.
I must stress that this is an exceedingly rare complication.
Note that the verbs deny and disagree add a negative meaning to what you are saying.
I disagree that it is a relatively easy matter to negotiate over hostages.
I phone twice a day but I can't deny I miss them.