Multiple realities
(covers information from several alternate timelines)

The following is a list of unnamed languages.

Caretaker's epitaph language

The language (top and bottom)

This language, along with the English language, was inscribed on the Keeper's epitaph. (TAS: "Once Upon a Planet")

Cytoplasmic lifeform's language

The language vocalized by the non-humanoid cytoplasmic lifeform encountered in the Delta Quadrant by the USS Voyager in 2375 was considered incredibly complex. The language consisted of a series of high pitched shrieks and screams. For humanoids, it was rather annoying and uncomfortable to listen to.

After Voyager received a message from this species, Captain Kathryn Janeway attempted to translate the language by instructing the computer to assign symbols to all the different tones in it, hoping to ascertain their meaning. There were over 10,000 different sounds in only one section of the message. In the end, the language proved indecipherable, its complexity far beyond the capabilities of the Federation to translate at the time of the encounter.

However, The cytoplasmic lifeforms could understand the Starfleet crew, probably through the use of a universal translator. (VOY: "Nothing Human")

Enterprise-D nursery alphabet

An unknown alphabet (top left)

This alphabet, along with the English alphabet, graced the wall of the USS Enterprise-D nursery in 2365. (TNG: "The Child")

Flaherty's languages

These languages, along with Romulan, Klingon, Giamon and Stroyerian, were spoken by Commander Flaherty as of sometime prior to 2365, according to Jean-Luc Picard. He mentioned it to William T. Riker that year when Riker inquired about the first officer of the USS Aries following his (ultimately rejected) appointment as the Aries's captain. (TNG: "The Icarus Factor")

As these languages also presumably include English, that would mean the unnamed languages numbered 35.

Gosis' species language

The written language

The species of Gosis had an own language. Writings of this language appeared on containers and on the radiographs created by Doctor Temec. (ENT: "The Communicator")

Makull's species language

Makull's species language

Writings of this language were written on a shop-window in the city. (VOY: "Time and Again")

Manas' language

This alien language was used by Manas in conversation with Krall.

In 2263 of the alternate reality, the fact that Nyota Uhura had only heard Krall use this language was responsible for her considerable surprise when he started to speak English to her. (Star Trek Beyond)

Nekrit supply station

The script

The script of an unidentified language was found on board Bahrat's supply depot in the Nekrit Expanse in the Delta Quadrant in 2373. (VOY: "Fair Trade")

Nezu planet writing

The script

Equipment with writing on it was present in a cavern at the base of an orbital tether on a Nezu-controled planet. (VOY: "Rise")

Patient 8923/3's mother tongue

Though she didn't know his species' name, Dr. Soji Asha spoke in Patient 8923/3's mother tongue during a procedure to remove his Borg implants aboard the Artifact in 2399. The uncommon level of respect shown drew the attention of Borg Reclamation Project Director Hugh. (PIC: "Maps and Legends", "The End is the Beginning")

D'kah pohket woken.
You are free now, my friend.

Ravis' language

See: Ravis' language

Swarm species language

The language of the Swarm species, a territorial and hostile Delta Quadrant species, was first encountered by the crew of the USS Voyager in 2373.

The language was so different from other known languages that it initially could not be translated by the universal translator. After some work on the UT by Harry Kim, a rough translation of the language became possible. A transmission in this language was roughly translated as "Too late...Should have listened." (VOY: "The Swarm")

Teenaxi symbols

Several symbols (bottom)

These symbols were seen at the base of a platform on which members of the Teenaxi Delegation stood in 2263 of the alternate reality. (Star Trek Beyond)

Webb's language

George Webb was allegedly heard muttering in what was described as "some sort of alien language" following his contact with an escape pod from a Y-500 class freighter, according to Travis Mayweather. (ENT: "Strange New World")

This language was only mentioned in dialogue.
The story of Webb was described as a ghost story, and so might not actually have happened.
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