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