some example: Dimmi dove sei stato ieri sera! (the jealous wife to her husband) Sai quanto costano i ristoranti a Ibiza? No, dimmelo tu che ci sei già stato.

Dimmi and dimmelo are imperative forms of the verb “dire”. Dimmi (=dire a me) means that you ask to someone to say something to you. The example of Simone is perfect. The wife wants to know where the husband was, so she says “Dimmi dove sei stato ieri sera!”. Other examples can be “Dimmi dove hai nascosto il mio cellulare”, “Dimmi dov´é la mamma!”. In dimmi there is the unstressed personal pronoun "mi" which means “a me” Dimmelo (= dire qualcosa a me) means that you ask to someone to say something already mentioned to you. Also in this case the example of Simone is good. The question or the conversation is about something specific. “Sai quanto costano i ristorante a Ibiza? No, dimmelo tu che ci sei giá stato”. Other examples can be: “Sai dove Marco ha nascosto il tuo cellulare? No, dimmelo tu!”, “Se non trovi il libro, dimmelo cosí ti aiuto a cercarlo”, “Se trovi la mamma, dimmelo!” In dimmelo there is the combination of unstressed personal pronoun "mi" and "lo" (unstressed personal pronoun). In such combination “mi” becomes “me”. Hope it helps. if you still have some doubts, just ask ;o)

a1) dimmi a2) dimmi un po` b1) dimmelo tu b2) dimmelo tu, se lo sai ===== Examples: e1) Dimmi, domani cosa fai? Vogliamo vederci nel pomeriggio? e2) Dimmi un po`, cosa ne hai fatto del libro che ti ho prestato un anno fa, ce lo hai ancora? e3.a) Lo sai Beethoven a chi ha dedicato la sua terza sinfonia? e3.b) Lo sai che io studio fisica, ne so poco di musica (I know just a little about music), dimmelo tu, se lo sai! (parent reproaching son) e4.a) Lo sai cosa mi ha detto il preside (school director) di te? e4.b) Non lo so proprio, dimmelo tu per favore. ==== In the previous examples: (e1) introduces an intimate talk, 'tu dimmi' usually shows affection or a close relation. (e2) with 'dimmi un po` ' shows impatient, or even a slight reproach, actually the speaker has been waiting that he len to a friend a for for over a year. In (e3) the speaker (b) using 'dimmelo tu' let speaker (a) know that he does not like his boasting of his vast musical culture, so 'dimmelo tu' is used as a challenge. In (e4) the child does not accept the implied reproach in the parent's sentence, and draws a line of defense using 'dimmelo tu'. These are typical contexts of usage of those expressions, many more could obviously be written.