1. The phrase qui pro quo, or quiproquo (from medieval Latin: literally qui instead of quo) is common in languages such as Italian, Portuguese, Spanish and French, where it means a misunderstanding.
2. Quid pro quo (From the Latin meaning something for something) indicates a more-or-less equal exchange or substitution of goods or services. English speakers often use the term to mean "a favor for a favor" and the phrases with almost identical meaning include: "what for what," "give and take," "tit for tat"...
> In those languages, the phrase corresponding to the usage of quid pro quo in English is do ut des (Latin for "I give so that you may give").
> Tit for tat is an English saying meaning "equivalent retaliation".
Italian: Qui pro Quo --> misunderstanding
English: Quid pro quo --> something for something
and
Italian: Do ut Des --> something for something
