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