Nouns ending in -s, -x, -z, -ch, or -sh add -es to form the plural. This makes the word easier to pronounce.
Duplex is regular. It follows the -es Addition rule.
Use plural verbs: "The duplexes are ready" (not "is ready").
Yes. The plural duplexes is standard across all English variants.
The word duplex follows the standard English pluralization rule. When forming the plural, duplex becomes duplexes. This follows the -es Addition pattern, which is one of the most common plural rules in English.
Understanding why duplex becomes duplexes helps with spelling and pronunciation. Nouns ending in -s, -x, -z, -ch, or -sh add -es to form the plural. This makes the word easier to pronounce.
When using duplexes in writing, remember that it functions as a plural noun in sentences. It pairs with plural verbs and pronouns. For example: "The duplexes are ready" (not "is ready"). This subject-verb agreement is essential for grammatical correctness.