These sounds are pronounced like in English with resonance in the nasal cavitity. Only [m] and [n] could be used as independent word-forming elements; the velar nasal only appeared by assimilation of [n] before velar consonants (SD/420, 432). Tolkien indicates that Primitive Adûnaic may once have had a palatal nasal [nʲ] as well for similar reasons ([n]-assimilation before palatals), but it used the same letter as [n] for this sound (SD/432).