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