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