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