Learn Farsi: کدام پرنده‌ی نارنجی را دیدی؟

In Farsi, the question word kodâm (which) is almost always followed by a singular noun, even if you are asking about a plural group or expect a plural answer. So we use the singular parande (bird) rather than the plural parandehâ.

Why does kodâm come before the noun, while nârenji comes after?

Question words like kodâm (which) and če (what) are exceptions to the usual rule and come before the noun they describe. However, regular descriptive adjectives like nârenji (orange) follow the normal rule and come after the noun.

Why is there an extra letter "ye" (ی) at the end of parande?

This is the Ezafe connector linking the noun "bird" to the adjective "orange". Because parande ends in a vowel sound (the silent "h" making an "e" sound), the Ezafe becomes a -ye sound instead of the usual -e, and is written with the letter "ye" (ی).

Why do we need the object marker râ (را) here?

The word râ shows that the direct object of the verb is specific or definite. Since you are asking "which" particular orange bird someone saw, the bird is a specific object, so it requires râ immediately after the noun phrase.

Where is the word for "did" in the Farsi sentence?

Farsi does not use helper verbs like "did" or "do" to form questions. The verb simply means "you saw". The sentence naturally becomes a question because of the question word and the rising intonation when spoken.