Copulas. In dealing with the copulas, colloquial Persian has two sets, which are added to words as suffixes, as follows.

The first set is used after consonants:

After [-i], with the exception of the first person singular and the third person singular and plural, an euphonic [ی] intervenes before the ending, and the three close fronts are glided upon:

ایرونی iruni ‘Iranian’:

Because of the cumbersome articulation, after [i] usually Persian speakers prefer to use the long copula hast– form with the second person singular and first person and second person plural, in which case the treatment is the same as in dealing with the terminal consonants:

خوب xub ‘good, fine’:

The first set is used after consonants:

The only terminal short vowel in Persian is [-e], which represents a classical [-a] (in most cases from a Middle Persian [-ag] suffix). In the case of the vowels the following must be considered:

With a terminal short vowel [e], the following set is used and an euphonic [ی] intervenes between the word and the second person singular and the first person and second person plural suffixes. With the first person singular, the [-e] becomes very weak and a glide occurs. With the third person singular the terminal [-e] is assimilated into the initial [a-] of the suffix. With the third person plural, it is optional to retain or drop the [-e]:

خونه xune ‘home; at home’:

With a long [ā], the following set is used. (Note that the [ی] in the second person singular and the first person and second person plural is euphonic.):

اینجا injā ‘here’:

With a long [u], the following set (including the euphonic [ی] explained above) is used:

ترسو tarsu ‘timid, pusillanimous’:

With a long [i], a set similar to [-u-] is used (including the euphonic [ی] explained above). However, to prevent a hiatus, often with the second person singular and the first person and second person plural the verb hastan is used:

راضی rāzi ‘content, satisfied, pleased’: