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Hi there ,
they are two tenses of the word "hast" (هست) in farsi and it equals to "to be" verb in english.
For example:
I "am" == هستم
(singular) you "are" == هستی
he/she "is" == هست
we "are" == هستیم
(Plural) you "are" == هستید
they "are" == هستند
as you can see, we have 6 tenses in persian.
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