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