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