Joan Bybee and her colleagues present a new theory of the evolution of grammar that links structure and meaning in a way that directly challenges most contemporary versions of generative grammar. This study focuses on the use and meaning of grammatical markers of tense, aspect, and modality and identifies a universal set of grammatical categories. The authors demonstrate that the semantic content of these categories evolves gradually and that this process of evolution is strikingly similar across unrelated languages.

Through a survey of seventy-six languages in twenty-five different phyla, the authors show that the same paths of change occur universally and that movement along these paths is in one direction only. This analysis reveals that lexical substance evolves into grammatical substance through various mechanisms of change, such as metaphorical extension and the conventionalization of implicature. Grammaticization is always accompanied by an increase in frequency of the grammatical marker, providing clear evidence that language use is a major factor in the evolution of synchronic language states.

The Evolution of Grammar has important implications for the development of language and for the study of cognitive processes in general.

Exploring Options is designed to help student writers develop their knowledge and use of academic language to meet the demands of college- and university-level writing assignments. It draws on the research identifying lexical and grammatical patterns across academic contexts and provides authentic reading contexts for structured vocabulary learning. Recognizing that vocabulary choices in writing often require consideration of grammatical structure, Exploring Options focuses on specific kinds of lexico-grammatical decisions—that is, the ones involving the interaction between vocabulary and grammar--that students face in shaping, connecting, and restructuring their ideas. The book helps writers learn how to effectively use resources such as learner dictionaries, thesauruses, and concordancers to improve academic word knowledge.
 
Following a unit on using resources for vocabulary development, the contents are divided into three parts: Showing Relationships within Sentences, Connecting and Focusing across Sentences, and Qualifying Statements and Reporting Research. Part 1 focuses on verbs and modifiers that express increases and decreases, verbs and abstract nouns that describe change, connectors and verbs describing causal relationships, and parallel structures. Part 2 explores the words that help connect ideas and add cohesion. Part 3 discusses how to express degrees of certainty and accuracy and the use of reporting verbs.