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