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