Personal endings of the verb “to be”—also called present copulas—which are affixed to the end of nouns or adjectives, with the exception of the third singular, are as follows:

Each of these copulas has all the information about the person, the number, and the tense. That is to say, for instance, خوبم (without the pronoun من) already means “I am fine.”

Orthographically after a long [ā] and [ū], normally an euphonic یـ or alef (and in certain cases, either of the two) intervene between the noun/ adjective and these copulas. The exceptions are in the case of the second singular, which invariably takes only the یـ, and the third singular, which either stays as است, or is contracted (that is, it drops the initial alef).

Since the segment یی is pronounced as ’i and not yi, from early times within the Arabicized era some writers/copyists started writing the segment phonetically a ئی, which historically and etymologically is incorrect. That is, writing تو دانشجویی as تو دانشجوئی and چه موی زیبایی as چه موی زیبائی is entirely incorrect. It must be understood that hamze is not a feature that belongs to Persian grammar; it belongs to Arabic and cannot replace a Persian feature, or be used with Persian words. In the following examples, the یی (ییم, یید) segment is transcribed as –yi, but it should be pronounced as –’i:

After the silent /h/ (and variably after /i/) an euphonic alef (never the یـ, with the exception of the second singular) is used:

Words ending in ی are inconsistence, as follows:

As Ferdowsi says:

من ایرانیَم ٬ این شعار من اسـت وطن دوســتی افتخـار من اسـت
چـو ایران نباشــد٬ تن مـن مبـاد بدین بوم و بر زنده یک تن مباد
man irāniyam, in šo’ār-e man ast vatan dusti eftexār-e man ast
co irān nabāšad, tan-e man mabād bedin bum-o bar zende yek tan mabād
‘“I am (an) Iranian,” this is my motto; patriotism (literally, loving the homeland) is my honor
Without Iran, may I cease to exist (literally, may my body cease to be);
May not even one soul (literally, body) exist in this land’

In this case Persian speakers are usually more comfortable using the long copulas (with the exception of the 3rd singular, in which case the long copula means a different verb, namely, ‘to exist’):

Note that the third singular است is a full grade verb, and not an ending.

Examples:

Nouns: Adjectives: