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