Stress is the degree of force or loudness given to a certain syllable. In some language including English and Russian, the stress position is variable and can not be predicted. Persian is among the languages that have fixed stress position. In Persian, stress falls on the last syllable. There are only a few exceptions and cases where word stress is not on the last syllable.

Word Part of Speech Syllables
آسمان
âsemân
(sky)
Noun â-se-MÂN
زیبا
zibâ
(beautiful, pretty)
Adjective zi-BÂ
شما
shomâ
(you)
Pronoun sho-MÂ
نوشتن
neveshtan
(to write)
Infinitive ne-vesh-TAN

In Latin alphabet, it is common to denote irregular stress position by placing the acute accent (´) above the stressed vowel. For example, in Spanish “corazón”. The same approach can be adopted for Persian words having irregular stress position: bále, ágar, ámmâ, zírâ.

Word Syllables
بله
bále
(yes)
BA-le
اگر
ágar
(if)
A-gar
اما
ámmâ
(but)
AM-mâ
زیرا
zírâ
(because)
ZI-râ