Questions & Answers about Onko tämä omena vielä syötävä?
How do we get the word syötävä from the verb syödä (to eat)?
You form the passive present participle by taking the passive stem. For syödä, the standard passive form is syödään. Replace the ending with -tava or -tävä (following vowel harmony) to get syötävä. It often translates to English adjectives ending in -ible or -able, making it mean "edible" here.
Could syötävä also mean "must be eaten" in this sentence?
Not in this specific sentence. While the -tava/-tävä participle is heavily used to express necessity, that structure requires someone in the genitive case who has to do the action. For example, Sinun on syötävä tämä omena means "You must eat this apple." Without a genitive subject like sinun, it simply acts as an adjective describing the apple.
Why is syötävä in the basic nominative case here and not the partitive (syötävää)?
In a standard "A is B" sentence, the describing word matches the subject. Because omena (apple) is a single, countable item, the adjective syötävä stays in the nominative case. If the subject were an uncountable mass noun like ruoka (food), the adjective would be in the partitive: Onko tämä ruoka vielä syötävää? ("Is this food still edible?").
Why is Onko at the very beginning of the sentence?