Nouns ending in -a (often Latin or scientific) add -e to form the plural.
Guinea is regular. It follows the -ae Addition rule.
Use plural verbs: "The guineae are ready" (not "is ready").
Yes. The plural guineae is standard across all English variants.
The word guinea follows the standard English pluralization rule. When forming the plural, guinea becomes guineae. This follows the -ae Addition pattern, which is one of the most common plural rules in English.
Understanding why guinea becomes guineae helps with spelling and pronunciation. Nouns ending in -a (often Latin or scientific) add -e to form the plural.
When using guineae in writing, remember that it functions as a plural noun in sentences. It pairs with plural verbs and pronouns. For example: "The guineae are ready" (not "is ready"). This subject-verb agreement is essential for grammatical correctness.