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