Star Trek: 9 Ways Strange New Worlds Re-Imagined The Gorn
4. Visual Communications
Several episodes of Star Trek have explored the varying ways that different species communicate. For example, in the Star Trek: The Next Generation episode Darmok, Enterprise-D makes contact with the Tamarians. While the universal translator can translate their words it can't decipher the way they're being used. Captain Picard is only able to communicate with the Tamarian captain when he realizes that they communicate with metaphor, citing examples from their myths and history as ways to deal with a current situation.
When Kirk and the Gorn captain faced each other, the Gorn captain communicated verbally just like the majority of aliens encountered by the Enterprise, the communicator that they'd each been given translated his hisses and grunts into English.
However, when La'an and her brother, Manu, were prisoners on the Gorn breeding planet, Manu discovered that the Gorn also communicated with flashes of light. He deciphered their code and gave her a key to their language..
La'an suppressed this memory but when the Enterprise was attacked by the Gorn over Finibus III, Spock helped her recover it through a mind meld. This recovered memory helped La'an and Spock use the Gorn visual language to turn the Gorn vessels against each other.