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