The language

Historically there are three major periods of development within the Persian language: Old Persian, the language of the Achaemenians (650 – 350 B.C.); Middle Persian (the Parthian period c. 350 B.C. – 230 A.D. and, immediately following that, the Sassanian period c. 230 – 650 A.D.), and New Persian, which starts to take shape after the Iranian conquest by the Arabian armies in the seventh century.
New Persian, in turn, can be divided into two major periods (regardless of the dialectal/regional variations): Classical Persian and Modern Persian.

Some Useful Phrases:

Phrases How to say Persian
How much is it? GHEYMATE IN KALA CHEGHADR AST? قیمت این کالا چقدر است؟
Where is this Address? IN ADDRESS KOJAST? این آدرس کجاست؟
How can I get to... Hotel? CHETOR MITAVANAM BE HOTEL... BERAVAM? چطور می توانم به هتل... بروم؟