The conditional clause introduced by "if", "when", or "should" in English is called the protasis, and the main clause is known as the apodosis. Conditional clauses regularly precede the main clause. Egyptian language as well as Arabic language have several methods to express conditional clauses. This research will deal with the most considerable particle in this meaning, i.e. "jr" as a conditional particle. It will be suggested that "jr" could act as an equivalent to each one of the following Arabic conditional particles: conditional amma أما الشرطية " lau لو الامتناعية وغير الامتناعية The Egyptian particle "r" will be analysed here from two different perspectives: 1- The origin of "jr". 2- The uses of "jr".