In the previous lesson, you learned the main elements of the Persian writing system, which ought to equip you with a decent understanding of the grand majority of Persian writings. Nevertheless, for works that are generally considered more advanced and delve into more advanced topics (e.g: religion, law, society,) more Arabic loanwords are likely to pop up, and as such, additional conventions will likely be seen in words. This lesson will go over the more common pieces of advanced Persian orthography.

Tanvin

Tanvin is almost always used in Arabic loanwords, indicating that the word ends with an "-an" sound. The word vagh'an (واقعاً), meaning "truly," has a tanvin at the end, showing that the word ends with an "-an" sound. Other examples include tab'an (طبعاً), meaning "naturally," and asāsan (اساساً), meaning "fundamentally."

Hamze (ء)

Hamze (ء) is a letter of Arabic origin which represents a glottal stop. Persian took the letter and changed it into a diacritical mark which appears on or after certain letters, and is therefore not considered a proper letter of the alphabet per se. 

Hamze is primarily used for separating vowels. Hamze is generally used for words that can often be mistaken for one another due to the similar fashion of spelling. The word ra'is (رئیس), meaning president or boss without the hamze becomes ris (ریس,) a completely different word.

Tashdid

The tashdid symbol (ـّ) is a diacritic derived from Arabic that requires the reader to geminate the consonant, like in the word shiddat (شدّت), meaning "intensity," the tashdid diacritic above the /d/ sound requires the sound in question to be geminated. Sometimes in casual Persian conversations, the tashdid is disregarded and simplified according to the will of the speaker for whatever reason.