Clinical Linguistics and Phonetics 18, no. 4-5 (June-August 2004): 235-57.
Linguistics can tell us what makes the poem incoherent, how the "speaker" is multiple, but not who the speaker is.
Both monolingual and bilingual French dictionaries can be found online, such as the monolingual Lexilogos or the bilingual French Linguistics dictionary that switches from French to English or from English to French.
Clinical Linguistics and Phonetics 18, no. 4-5 (June-August 2004): 341-55.
Resources for Tolkien Linguistics - This is an academic site that has devotedly explored the nuances of Tolkien's languages.