Rarely does a debut novel make a reader hunger for the author's next book, but anticipation is precisely what one feels after reading ''A Cab Called Reliable,'' by Patti Kim. Both elegantly and humorously told, it is the story of one young woman's attempt to ''span the breach between what-is and what-ought-to-be.'' For the Korean-American narrator, Ahn Joo Cho, ''what-is'' is at first dispiriting and lonely. She is 9 years old when her mother suddenly packs her baby brother into a taxi and leaves town, finally escaping what, in her parents' endless fights, her mother always calls ''a dog's life.'' Ahn Joo is left without a clue to her mother's whereabouts, caught in an unfamiliar America while still tied to an oppressive Korean tradition in which women are mainly valued for the services they provide and not for who they are or might become. She also has sole responsibility for her increasingly hard-drinking father. Initially, Ahn Joo clings to him, despite his meanness and disregard for her, fearful that he too will disappear. Then school introduces her to the power of language. As she learns the meanings of words, she becomes fascinated by them, especially words like ''reliable,'' the name of the cab company that whisked her mother away. As time passes, it also becomes clear that words will provide her with the strength and skill she needs to help her father and free herself. In tracing this progress to independence, Kim uses a precise and assured storytelling voice, one that manages to be both artless and accomplished.