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