Science fiction that deals directly with language is kind of rare, which is a pity because the question of how we would communicate with aliens if we ever encounter any is one of the most interesting problems in science fiction. Too often the problem is waved away with a magical "universal translator" device.
In Embassytown Mieville creates a race of aliens that pose a number of communication problems. First, the Ariekes have two mouths and their words consist of two different sounds spoken simultaneously, making it impossible for a human to speak it alone. Second, the Ariekes are mildly telepathic, so two humans speaking the two part words in perfect synchronization are still not enough, there has to be a single thought behind the two speakers. For this reason cloned ambassadors are raised from birth to function as a unit just to communicate with the aliens. Finally, because of the telepathy underlying their spoken language Ariekes are extremely literal, for this reason the can only use a simile if someone acts it out first.
The narrator of the novel is a living simile in the Arieke language. She is "the girl who ate what she was given" which is used to mean making do with what is available. The novel is her account of how Embassytown was almost destroyed by a situation arising from this awkward way of communicating. I will not spoil the details, but it is much more creative than the fictional miscommunication cliche of the foreign dignitary who takes offence at an innocent gesture that means something different in his culture.
The 4 stars are for the brilliantly realized alien civilization in the novel. The story itself is quite good, but I found the ending surprisingly unsatisfying. I can see where Mieville was trying to go with the ending, but it feels very deus ex machina and I wish he had spent a little more time developing the solution into something a bit more plausible.