Farsi / Persian 

Farsi, also called Persian, is spoken mainly in Iran, but also in
Iraq, Oman, Qatar, Tajikistan and the United Arab Emirates. Dari,
which is one of the main languages of Afghanistan, is virtually the
same in its written form.  

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Information

Sentences for Travellers

Phrases

More phrases

Pronunciation of Farsi

Grammar

Extensive Farsi course with Audio, also teaches the writing
Another course, for children
CRE Farsi course for aid workers 

Quiz

Learn Farsi vocabulary

Free help translating a phrase from/to Farsi

Professional (paid) translations from/to Farsi 

Resources for offline learning:
Farsi/Persian electronic dictionaries, translators & software
Farsi-English-Farsi dictionary
Course: Colloquial Persian
Course: Persian self-teaching method
Course: Language 30 Persian
Lonely Planet Farsi phrasebook
Persian grammar
More...
Persian / Farsi products from worldlanguage.com

Misc:
Tongue Twisters in Farsi
Learn to curse in Farsi