Khuzdul

He based its structure and phonology on Semitic languages, primarily Hebrew, with triconsonantal roots of words.

Tolkien began developing Khuzdul before the publication in 1936 of The Hobbit, with some names appearing in the early versions of The Silmarillion.

[1][2][3] Tolkien noted some similarities between Dwarves and Jews: both were "at once natives and aliens in their habitations, speaking the languages of the country, but with an accent due to their own private tongue…".

Aulëan was named from the Dwarvish tradition that it had been devised by Aulë the Smith, the Vala who created the Dwarves.

The Dwarvish sign language was much more varied between communities than Khuzdul, which remained "astonishingly uniform and unchanged both in time and in locality".

[T 4] Tolkien described its structure and use: "The component sign-elements of any such code were often so slight and so swift that they could hardly be detected, still less interpreted by uninitiated onlookers.

As the Eldar eventually discovered in their dealings with the Naugrim, they could speak with their voices but at the same time by ‘gesture’ convey to their own folk modifications of what was being said.

2 Supposedly in Azaghâl, 'gh' [ɣ] is used to represent this sound in Black Speech and Orcish, but wasn't said of Khuzdul.

The dwarves had adopted the Cirth from the elves by the end of the first age, and made changes to their liking to represent the sounds of Khuzdul.

Tolkien states that Khuzdul was complicated and unlike the other languages of Middle-earth at the time in its phonology and grammar.

[1] Nouns and adjectives had singular and plural forms and, like the Semitic languages, can be in the absolute or construct state.