Traduko - Rumana-Franca - nu te cred costele , vorbesti romaneste

Francky, it isn't "parle",it is "parles" because "vorbeşti româneşte" is 2nd person sg.( "(tu) vorbeşti româneşte" = "(tu) parles roumain".

Thanks for the intention, Freya, but the verbe "parler" belongs to the first group (verbs ending in "er" at the infinitive). And these verbs, when at the imperative form, do not have an "s" at their end at second person singular
Have a look here

I know the imperative, but the sentence doesn't have a exclamation mark...oops the original doesn't have an exclamation mark !! sorry(I first look at the phrase in Romanian).Yes, you are right because the French translation has exclamation mark at the end. Mes excuses!

On second thought, exclamation or not, I know Romanian very well and "vorbeşti româneşte" is not an imperative form. If it were an imperative it should have been "Vorbeşte româneşte!" (Speak Romanian !).The form " Vorbeşti româneşte" is present 2nd person sg. Maybe, in the end, these signs should be better " ? ! " or even no sign at all This happens when you put exclamation where it isn't any
take a look here for the verb "a vorbi"
For understanding better, the phrase is something like this :" I don't believe you ,Costele! You really speak Romanian ? ! " (it's not really a question, it is more like a "surprise" for the person who says that.) or another explanation could be "I don't believe you, Costele! You speak Romanian (you speak Romanian and not other languages)...anyway, it depends on the context, but all I can say is that "vorbeşti româneşte" is not imperative.

So if it isn't imperative, we French gotta use the pronoun before the verb, as only the imperative reads that way in French.
I'll edit the French text with "tu parles roumain"
Thanks for the help Freya!

merci a tous pour votre aide