Clitics are words or more precisely, “morphemes” that have a distinct grammatical role but they lack stress and as a result, they are phonologically dependent on their leading or preceding word. Clitics that are related to their leading word are called proclitics and clitics that are related to their preceding word are called enclitics. Clitics form syllable with their host word and change its original syllable structure and stress position.

Persian’s indefinite article “i” is an enclitic. In the word “pedar” (father), the syllable structure is pe-DAR and the stress is on the last syllable. When it takes the indefinite article i.e. “pedar-i” (a father), the syllable structure becomes pe-DA-ri and the stress shifts to the penultimate syllable. The indefinite article lacks stress. Therefore, the stress position can not remain on the last syllable and it shifts one syllable back.

Compare the enclitic “i” in “pedar-i” (a father) with the suffix “i” in “pedari” (paternal). Suffixes do not affect stress and as a result, “pedari” has the syllable structure pe-da-RI with the stress on the last syllable, which is the default stress position in Persian. Both of these have the same written form. The context determines whether “i” is an enclitic or a suffix.

Suffix “i” Enclitic “i”
روستای پدری
rustâ-ye pedari
paternal village
پدری روستایی
pedar-i rustâyi
a rural father

Even though clitics are phonologically dependent on their host word but they have a distinct grammatical role and are syntactically independent. Therefore, they should be written separately. In Middle Persian, enclitics were written as separate words but in New Persian, the majority of enclitics are written attached to their host word. For educational purposes, the following enclitics are separated from their host word with a hyphen:

Enclitic Latin Script Persian Script
genitive marker dust-e man
khâne-ye man
دوست من
خانه‌ی من
Indefinite Article mard-i
Bound Personal Pronouns ketâb-ash