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