Learn Farsi: من هزار کتاب دارم.

The verb dâshtan (to have) is a special irregular verb in Farsi. While most verbs need the mi- prefix to show the present tense, dâshtan doesn't use it. You just take the present stem dâr- and add the personal ending, which in this case is -am for "I".

The translation says "books" (plural), but ketâb doesn't have the plural ending -hâ. Why is it singular here?

In Farsi, whenever you use a specific number before a noun (like hezâr meaning "thousand"), the noun must stay in its singular form. So, instead of saying "a thousand books", Farsi literally says "a thousand book" (hezâr ketâb).

In English, we say "a thousand". Do I need to add the Farsi word for "one" (yek) before hezâr?

You don't have to! Just saying hezâr naturally means "a thousand" or "one thousand". While you could technically say yek hezâr, just hezâr is much more common and sounds perfectly natural.

Since dâram already means "I have", do I really need to include the pronoun man (I) at the beginning of the sentence?

It is completely optional! The ending -am on dâram already tells the listener that "I" am the one who has the books. Including man just adds a little emphasis, but dropping it is very common in everyday Farsi.