Greek-derived nouns ending in -on change to -a in the plural form.
Onion is regular. It follows the Greek -a rule.
Use plural verbs: "The onia are ready" (not "is ready").
Yes. The plural onia is standard across all English variants.
The word onion follows the standard English pluralization rule. When forming the plural, onion becomes onia. This follows the Greek -a pattern, which is one of the most common plural rules in English.
Understanding why onion becomes onia helps with spelling and pronunciation. Greek-derived nouns ending in -on change to -a in the plural form.
When using onia in writing, remember that it functions as a plural noun in sentences. It pairs with plural verbs and pronouns. For example: "The onia are ready" (not "is ready"). This subject-verb agreement is essential for grammatical correctness.