Final answer:
The rules for transforming a singular noun ending in -ix, -ex, or -yx into its plural form involve changing the ending to 'ices' or 'es'. The suffix '-ess' is used to form feminine nouns from masculine nouns, and the addition of 's' or 'es' for plurals and possessives depend on the existing ending of the noun.
Step-by-step explanation:
When the singular form of a word ends in -ix, -ex, or -yx, change the 'ix', 'ex', or 'yx' to 'ices' or 'es' to form the plural. For instance, the plural of 'index' is 'indices' or 'indexes', and the plural of 'matrix' is 'matrices' or 'matrices'. This transformation is a part of English spelling rules concerning words ending with certain suffixes.
Another example of a suffix is -ess, which is used to form female nouns from male nouns. For example, 'host' becomes 'hostess'.
Suffixes can also indicate tense or plurality in verbs and nouns. Add '-es' for words ending with 'y' after a consonant, like 'sky' becomes 'skies'. When adding possessive 's to plural nouns, the placement depends on whether the noun already ends with an 's'. For example, 'the children's game' (no 's' ending) vs. 'the friends' cars' (with 's' ending).