Learn Farsi: آیا هیچ کاستی در فروشگاه پیدا کردید؟ - Did you find any shortcoming in the store?

While hich usually means "nothing" or "none" and requires a negative verb in statements, it translates to "any" when used in a question and takes an affirmative verb. If this were a statement like "You didn't find any shortcoming," you would use the negative verb peydâ nakardid.

How does the word kâsti (shortcoming) fit into the topic of derivational morphology?

While this lesson focuses on forming nouns with the past stem + -âr, kâsti is a great example of a very similar pattern. It is formed by taking the past stem of kâstan (to decrease/reduce), which is kâst, and adding the abstract noun-forming suffix -i.

Is the -i at the end of kâsti the indefinite article meaning "a" or "some"?

No, the -i here is entirely built into the word as a derivational suffix (turning the stem into a noun). When using hich (any) to ask a question, Farsi often just uses the bare singular noun without needing to add an extra indefinite -i suffix to it.

How is the noun forushgâh (store) constructed?

It is built using forush, which is the present stem of the verb forukhtan (to sell), combined with the suffix -gâh, which indicates a "place of." Literally, it translates to "selling place."