A little preamble; this is my fourth China Miéville book (King Rat, The City and the City, and Kraken), and with Embassytown, and a big part of what I love about each of these is how he plays with genre and concepts in his faction.
In Embassytown much of what we look at is alien and language. Considering how tricky human languages are here on Earth (for example, did you know that there is no term in French for cool (as in temperature?) - just take a second and think of how much that alters the average francophones world view in terms of temperature), imagine how tricky it would be for a language with absolutely no shared points of interest.
The novel follows a woman named Avice Benner Cho, a child raised on the world of Arieka in the city of Embassytown who grows up to become an "immer", someone able to travel through an area of space around the world called the immer. The world itself is shared with an alien species called the Ariekei (also referred to as The Hosts), who have a concept of language that take a while get your head around.
The novel follows some key events in the city throughout the life of Avice and focuses largely on how different cultures work to understand each other without many shared reference points - for example the aliens don't really view most humans as sentient.
Although this wasn't my first experience with SF focused on questions of language, it was definitely the most immersive one I've ever come across.