There is some evidence that a feminine noun ending in -ê (and -î?) could add a linking consonant n between it and the following î in plural formations, to better distinguish it from the singular (SD/438): there are two alternate plural forms of izrê “sweetheart, beloved”: izrênî (normal plural) and izrênîm (subjective plural). Without such a linking consonant, the normal singular and plural forms would both be identical (both izrê) according to the rules of vowel-combinations.

Tolkien provides no examples of such a linking consonant for feminine nouns ending -î. Such nouns also have identical singular and plural forms, though, so perhaps they could also use the linking consonant n. Elsewhere Tolkien said that feminine nouns were frequently made to end in -ê instead of -î to better distinguish them from plural forms (SD/438), so perhaps such a change was preferred to linking consonsants.