In English we have the word "verisimilitude", meaning the appearance or semblance of truth.
1595-1605; < Latin vērīsimilitūdō, equivalent to vērī (genitive singular of vērum truth) + similitūdō similitude
It seems to translate the general point of it, but I would see "for real" as slang, so it would seem like unnecessary paraphrasing during translation to me.
Not that I'm not guilty of that to some extent sometimes, but changing "true" to "for real" could make the sentence a bit smartassy when it originally wasn't.
Jes, jes, estas vere.
Jes, jes, estas ver'.
Se ne kredas vi.
do venu konvinkiĝi pri l'afer'.
Oh, YOU aren't the denaskulo... in that case, let me add -- I don't think he/she should be correcting you like that. I'd be happy to discuss the reasoning here with this person, but being a denaskulo doesn't make one an expert in Esperanto. Far from it. (I know first hand from many denaskuloj.)