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