Only است ast ‘is’ is a full grade verb in this set of pronoun personal endings.

With the exception of[tag resources personalendings_13] است[/tag], the rest of the endings are the same in the written and spoken dialects.

In colloquial Persian[tag resources personalendings_14] است [/tag]becomes –e. Thus, for example, the formal would be خوب است xub ast ‘it is good,’ and the colloquial خوبه xube.

The endings are used in the conjugation of the verb “to be”. They are attached to the end of nouns and adjectives:

[tag resources personalendings_15]من ایرانیَم، ایرانی ام[/tag]
man irāni-am
‘I am Iranian, I am an Iranian.’

[tag resources personalendings_16]تو خوبی [/tag]
tó xubi
singular, ‘You are good.’

[tag resources personalendings_17]او دانشجو است [/tag]
u dānešju ast
‘He/she is a college student.’

[tag resources personalendings_18]ما خوشحالیم [/tag]
mā xošhāl-im
‘We are happy.’

[tag resources personalendings_19]شما پزشکید [/tag]
šomā pezešk-id
plural and formal, ‘You are a physician.’

[tag resources personalendings_20]آنها دکترند، دکتر اند [/tag]
ānhā doctor-and
‘They are physicians.’

[tag resources personalendings_21]ایشان معلّم اند، معلّمند [/tag]
īšān mo’allem-and
formal ‘He/she is a teacher.’

Notice that in spoken Persian,[tag resources personalendings_22] ایشان [/tag]does not mean “they” any more. In written materials ایشان could mean “he, she” or “they” and it may be figured out within the context.

When a noun or adjective ends in a vowel, a euphonic [-y-] (which is variably substituted with an alef) intervenes. This does not occur before است:

[tag resources personalendings_23]من اینجا اَم [/tag](most common)
[tag resources personalendings_24]من اینجایَم [/tag](rarely used)

[tag resources personalendings_25]تو دانشجویی [/tag](most common)
[tag resources personalendings_26]دانشجوای [/tag](rarely used)

[tag resources personalendings_27]ما خانه ییم [/tag](less common)
[tag resources personalendings_28]خانه ایم [/tag](more common)

[tag resources personalendings_29]شما تهرانی اید [/tag](more common)
[tag resources personalendings_30]تهرانی یید [/tag](rarely used)

[tag resources personalendings_31]آنها ایرانی اند [/tag](very common)
[tag resources personalendings_32]ایرانیند [/tag](rarely used)

Since in any case after the vowels a hiatus, or clash of two vowels, occurs, a Persian speaker is more comfortable using the full grade verb “to be”; that is, the verb هستن:

[tag resources personalendings_33]من اینجا هستم[/tag]
man injā hastam
“I am here.”
[tag resources personalendings_34]تو دانشجو هستی[/tag]
to dānešju hasti
“You are a college student.”
[tag resources personalendings_35]ما خانه هستیم[/tag]
mā xāne hastim
“We are home.”
[tag resources personalendings_36]آیا) شما تهرانی هستید؟) [/tag]
(āyā) šomā tehrāni hastid?
“Are you from Tehran?”
[tag resources personalendings_37]آنها ایرانی هستند[/tag]
ānhā irāni hastand
“They are Iranians.”