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