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