THE LETTER X IN ARTIFICIAL AUXILIARY LANGUAGES Dr. Alan Reed Libert School of Humanities & Social Science, Callaghan, NSW, Australia Alan.Libert@newcastle.edu.au, phone: 61-422-561-476 ORCID ID: 0000-0003-1446-4183 ABSTRACT In English and some other languages, the letter x is relatively rare and might be seen as exotic. In fact, it does not occur at all, or only in foreign words in some languages, for example, Turkish. On the other hand, there are languages such as French and Somali in which x might be slightly more common, although still not one of the most frequent letters of the alphabet. One might also notice that x can stand for different sounds in different languages, or even in the same language; for example, in English it usually represents [ks], but it can also represent [z]. These are facts about natural languages; the present paper will look at such facts in artificial languages, i.e. languages which have been consciously created, and in particular, artificial languages which were designed to be used for international communication, artificial auxiliary languages. The best known such language is Esperanto. The main questions will be whether x occurs in a language, and, if so, what sound(s) does it represent? Also, although letter frequency statistics do not exist for most artificial auxiliary languages, one might be able to get some idea of the frequency of x by examining whether it occurs in common words and/or affixes. Some artificial auxiliary languages, for example Kah and Uropi, lack x. Other languages, for example Neo, have x in their alphabet and it stands for the sequence of sounds ks. In still other languages, such as Ardano and Atlas, x is pronounced like sh in English. In Latino Moderne x has the same two pronunciations as it does in English. We thus see diversity in the function of this letter in artificial languages, as well as in natural languages. Keywords: Artificial languages, Letter frequency, Orthography, Alphabets, Spelling systems