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