This is the 23rd most frequent Persian word.
من
"I" or "me" (first-person singular pronoun).
In this sentence, 'من' is used as a pronoun that refers to the speaker in the first person singular form, effectively meaning 'I'.
من یک کتاب دارم.
I have a book.
Here, 'من' serves as the subject of the sentence, indicating that the action (going to school) is performed by the speaker.
من به مدرسه میروم.
I go to school.
In this example, 'من' is used in its possessive form, referring to the speaker in a phrase indicating agency or responsibility for an action.