The copula です (desu) is thought to be a contracted version of であります (dearimasu), from で (de) + あります (arimasu); however, there are other possibilities, namely でございます (degozaimasu), from で (de) + ございます (gozaimasu); でする (desuru), from で (de) + する (suru); でおわす (deowasu), from で (de) + おわす (owasu); and でそうろう (desourou), from で (de) + そうろう (sourou).
>>5600188
The final vowel in desu, "u" is unvoiced in the standard tokyo dialect, and in rapid speech is nearly indistinguishable to an untrained ear from not being pronounced at all. This gives rise to what foreigners would hear as "dess" which perhaps true in some sense, is really just a realization of the underlying phoneme of "de su"
>>5600188
Die you fucking animefag
>>5600188
unchecked dubs
>>5600203