Learn Farsi: خیاط یا پارچه یا نخ می‌آورد. - The tailor brings either fabric or thread.

In Farsi, you create "either... or..." by placing the word yâ (or) before both options. Literally, the sentence says "or fabric, or thread." This double use of yâ is the standard way to express "either X or Y."

Where do we place the yâ... yâ... phrase in the sentence?

Because Farsi is a Subject-Object-Verb language, the verb goes at the very end. The entire "either... or..." phrase acts as the object of the sentence, so it is sandwiched between the subject khayât (the tailor) and the verb mi-âvarad (brings).

Why doesn't the object phrase yâ pârche yâ nakh use the direct object marker râ?

We only use râ for definite or specific direct objects (like "the fabric" or "that thread"). In this sentence, the tailor is bringing "fabric" or "thread" in a general, indefinite sense, so no râ is needed.

What is the infinitive for mi-âvarad, and how is this form built?

The infinitive is âvardan (to bring). To make the present tense, we use its present stem, which is âvar. We add the continuous prefix mi- and the "he/she/it" ending -ad to get mi-âvarad (he/she brings).