Trying to remember the title of the novel I thought Arrival was based on

Question

When I saw the O-shape of the alien language in the trailer for Arrival I thought "Ok, I already know the plot and how it ends". Today I discovered that the plot was instead taken from "Story of Your Life", which I have never read. At this point, finding the title of "my" novel has become a matter of principle. What I remember for sure is that:

• The protagonist is a linguist
• She is contacted (Government? Military?) and taken to the landing site of an alien spaceship (somewhere in the United States?) where a base camp has been set up.
• The graphic sign shown to her is a kind of O (that's why I thought it was this novel)
• Humanity has a certain amount of time to learn the new language. If not able, it will be wiped out.

It turns out that the whole language is based on absolute coherence between thoughts and words, that is, on complete sincerity. It is a language in which it is impossible to lie. Only if humanity is able to learn it will the aliens welcome it into the great federation (or whatever it is) that is out there. Otherwise it will be wiped out, except for some specimens that will be saved and used as a warning to show at the next encounter with new races and new planets. Like the two teachers, who (twist!) don't belong to the race running the game, but are actually two survivors of another race that failed.

Does this remind anyone of anything?

Answer 1

You are remembering a short story not a novel. Specifically, the story is Try to Remember by Frank Herbert. It has been identified before in the questions Science Fiction short story about learning to communicate with aliens and What short story is about an alien race that threatened to blow up the world if we didn't decode a message?

There are some slight differences from your description. The protagonist Francine Millar is a clinical psychologist not a linguist, and she isn't shown a symbol in the shape of a circle, but apart from this it's a close match.

At the end of the story it is revealed that the five Galactics are:

"Those five are among the eight hundred survivors of a race that once numbered six billion," said the voice.

...

The voice from the ship rolled on: "This once great race did not realize the importance of unmistakable communication. They entered space in that sick condition—hating, fearing, fighting. There was appalling bloodshed on their side and— ours—before we could subdue them."

A scuffing sound intruded as the five green-skinned figures shuffled forward. They were trembling, and Francine saw glistening drops of wetness below their crests. Their eyes blinked. She sensed the aura of sadness about them, and new tears welled in her eyes.

"The eight hundred survivors—to atone for the errors of their race and to earn the right of further survival—developed a new language," said the voice from the ship. "It is, perhaps, the ultimate language. They have made themselves the masters of all languages to serve as our interpreters." There was a long pause, then: "Think very carefully, Mrs. Millar. Do you know why they are our interpreters?"

The held breath of silence hung over them. Francine swallowed past the thick tightness in her throat. This was the moment that could spell the end of the human race, or could open new doors for them—and she knew it.

"Because they cannot lie," she husked.

Answer 2

Embassytown is a story by China Miéville featuring a human linguist on a planet where the native intelligent species uses a language in which it is impossible to lie.

It sounds like you may possibly have mixed up details of Embassytown and Arrival, but in the former there is indeed an urgent and existential need for humans (and other species living in the world's town for non-native species) to develop more advanced linguistic capability with the natives, who (along with other issues) cannot understand languages besides their own.

It is also possible that you are thinking of yet some other book. :)