Just as in English, where expressions occur like to tell you the truth, I am not ill at all, in Latin there are expressions like (9):
(9) ut verum tibi dicam, pater, ea res me male habet (`To tell you the truth, father, this business makes me sick', Pl. As. 843)In a case like this a paraphrase like ea res me male habet `with the intention to … ' is impossible. What the speaker wants to say is that in his statement ea res me male habet he intends to tell the truth. The content of the ut-clause is a kind of explanation of the intention of the speaker. Such an ut-clause, like those in (7) and (8), can be taken to specify the utterance as such, rather than the content of the sentence. Note that it is meaningless to ask cur ea res te male habet? :: ut verum tibi dicam. Adjuncts with the semantic function Purpose, on the other hand, can form the answer to such a question. To explain this it is often said that the real main verb, a verb of saying, has been omitted.  General examples are:
(10) ego adeo, ut tu scias, prorsum Athenas … abibo (`just to tell you, I am immediately going to Athens', Pl. Mil. 1192)
(11) Carthagini ego sum gnatus, ut tu sis sciens (`I was born in Carthage, you ought to know', Pl. Poen. 1038)The difference in status between this type of subordinate clause (so-called `pseudo-Purpose' clauses) and `real' Purpose satellites explains, among other things, the possibility of using them in one sentence: To tell you the truth, I am on my way to the market in order to buy vegetables.  I have not yet found Latin parallels for the English example given here. [4a]
Pinkster, Harm (1942-) , Latin Syntax and Semantics [info], xii, 320 p.: ill.; 24 cm. [word count] [Pinkster].