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