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