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