The language is the means to communicate and the most important measure of the identities and beliefs; thereby it's of a great importance. The language is an dynamic and varying phenomenon, which is renewed continuously, and grows in the human domains and mediates thecommunications of the communities, as a result, it is permanently affected by the evolutionary dialectic and the laws ruling over the societies. Hence, it's needless to point out that it's worthy to learn a language, and what's better than Persian to learn! The Persian language is an Indo-European language which is spoken in Iran, Afghanistan, Tajikistan and some parts of Uzbekistan. It's also the official language of Iran and Tajikistan and one of the two official languages of Afghanistan (Pashto is the other one), and was the official language of India, before British colonization. Today, there are hundreds of Persian TV and radio channels, and even some important media in the world offer Persian programs like BBC, Euronews, national geographic, and etc. Also, Persian is widely used in some important web companies like google. Moreover, it's taught in some high rank universities. Since there are a lot of formal Persian language sources, whether books or data on web, and informal Persian is rarely found, we tried to provide a comprehensive and easy source of informal Persian grammar and conversation.In this book, we teach the beginner informal Persian in three sections namely: Grammar, Conversations, and Vocabularies, and the accent used in this book is the regular Tehrani accent. Also, we don't focus on teaching Persian alphabets, therefore we use Latin alphabet to show the pronunciation.