Clause grammar of English has been located at a critical, if not central, position in grammar research and has received extensive coverage over the past few decades.Footnote ^[1] In this book, Clarence Green focuses on the clause system from the perspective of clause combination, i.e. the integration of clauses with different levels of dependence upon each other and in relation to their main clause. While this is not a new dimension to approach the system, Green’s study distinguishes itself by discussing how the forms and functions of clause combination develop over time, which is an under-researched topic in clause combination research. Furthermore, drawing on corpus tools and methods, Green presents a substantial analysis of clause combination, which provides technological insights for other grammar studies. Another noteworthy point is that the book is integrated by the relationship between the clause system and cognition, which is based on Givón’s (Reference Givón1979, Reference Givón, Heine and Narrog2012, Reference Givón2015) Adaptive Approach to Grammar, the main framework of this book. Readers not familiar with it can also be expected to understand its major theoretical claims.

Green presents readers with a well-organized book consisting of eight chapters. Chapters 1, 2 and 3 revolve around the English clause system in contemporary language use. In the opening chapter, Green introduces the reasons for writing this book. The most straightforward reason is that human communication is overwhelmingly a series of connected propositions (Halliday Reference Halliday1985: 216) rather than a series of isolated or decontextualized utterances. In this respect, the study of clause combination has theoretical and empirical significance for the understanding of human language and communication. The challenge of describing the clause system for students and teachers constitutes another major reason, since there is much less agreement upon how to describe it than there is about other grammatical features (2). This may be far more conspicuous and challenging for teachers of English as a foreign language like I and my colleagues, who frequently receive questions from confused students concerning constructions, features and functions of English clauses. Drawing on a critical review of three main approaches to the English clause system, i.e. the scientific description of English grammar, the corpus-based study of speakers’ language use, and Systemic Functional Linguistics, Green constrains his framework to Givón’s Adaptive Approach to Grammar, a functional-cognitive model of grammar, which is given a preliminary introduction in this chapter. Givón makes two major claims about the model: (i) grammar is a coherence system that indexes various relationships in discourse, and (ii) language develops along a hierarchy from ‘looser’ constructions to ‘tighter’ combined clauses. Green adopts it as the framework of his book because it positions clause combination at its center and has important implications for understanding the system. He also notes that Givón’s theory is not universally accepted, so he conducts a couple of falsifiable research experiments to test the assumptions and explanatory power of this model.

Since linguists and grammarians do not share a widely accepted description of the English clause system, Chapter 2 reviews in more depth these disagreements and addresses some of the difficulties in describing the clause system. Green compares the clause systems presented in some of the most widely referenced grammars of the English language in current use, i.e. function-first descriptions of the English clause system including The Collins Cobuild English Grammar and A Comprehensive Grammar of the English Language and form-first descriptions of the English clause system including The Longman Grammar of Spoken and Written English and The Cambridge Grammar of the English Language. Resourceful and helpful as they are, Green argues, neither of the two descriptions recognizes the clause system as a clause hierarchy organized by a set of clauses with different degrees of dependence upon one another. Therefore, Green develops a synthesized model of the clause system, arguing that well beyond the dichotomy of coordination and subordination described in the above grammars, English clauses exist along a grammatical cline progressing from looser to tighter integration (36), which is in accordance with the view upheld by Givón and others.

A hierarchy of constructions brings forth the notion of gradience, referring to different degrees that a clause depends upon another, a central topic explored in more depth in Chapter 3. According to Green, each of the clause categories along the hierarchy has a range of subtypes. However, it is difficult to draw categorical boundaries between each subtype and therefore it is perhaps better represented by a fuzzy grammar. Where one category (subtype) begins to leak into another, a grammatical boundary has been captured in linguistics by the term ‘gradience’ (Givón Reference Givón1993, De Smet Reference De Smet2013). Within each clause category, the subtypes exhibit different degrees of resemblance to the most prototypical one with particular grammatical features. For example, within finite clauses, content clauses are the tightest, followed by relative clauses, comparative clauses, adverbial clauses, asymmetric coordinate, and symmetric coordinate. Furthermore, some clause categories also demonstrate gradience with other clause categories, from central to gradually marginal, i.e. from ‘tighter’ to ‘looser’. For example, a non-finite clause (I’ve got a lot of problems   is tighter than a semi-finite clause (She loves the house   This fits the nature of clause system more than the dichotomy discussed in Chapter 2 and therefore it is an innovative contribution to the description of English clause system.

In Chapter 4, a series of corpus studies (using the Penn Parsed Corpora of Historical English and the York–Toronto–Helsinki Parsed Corpus of Old English Prose, hereafter PENN–YCOE) are conducted to investigate the historical development of clause combination and the validity of two major theoretical claims about grammar. The generative Inertial Theory (Longobardi Reference Longobardi2001) claims that usage frequencies tend to remain stable over long periods of time, and the Adaptive Approach to Grammar maintains that language exists along a diachronic continuum from ‘looser’ to ‘tighter’ grammatical constructions. Using a large-scale quantitative analysis, this chapter reveals that the historical development of the clause system also exhibits a grammatical trend as a hierarchy. This, once again, testifies the claims of the Adaptive Approach to Grammar from the diachronic perspective. Nevertheless, this chapter also finds some unusual frequency distributions (e.g. the sharp rise of relative clauses at 1250–1350 ad contrary to the overall downward direction in the whole corpus) of a few clauses, which are given a closer examination and explanation in the following chapter.

In Chapter 5, using the PENN–YCOE corpus, Green conducts a more exhaustive investigation of various clauses on the hierarchy, trying to find whether the diachronic trends reported in Chapter 4 are shared across different genres and dialects in the history of English. Eight genres (bible, biography, fiction, handbook, history, treatise, laws, and philosophy) with the most robust sample distributions and another five genres (sermons, homilies, trials, public letters, and private letters) with very limited sample size and time distribution are investigated, showing that although the various genres demonstrate different frequencies of a couple of particular clauses, they share historical trends in most clauses, that is, tighter combined clauses tend to have higher frequencies than the looser ones. Adverbial clauses, the loosest combined clause along the hierarchy organization, demonstrate more stability across time than almost all other clauses. Present participle clauses are the only type that is hardly influenced by genre variation across time. With respect to dialect variation, the conclusion is similar to that of genre. The analysis shows that despite a few occasionally unusual frequency distributions, dialects exert little influence on the general trends of combined clause distributions. It also reveals that during the transitional period from Old English to Middle English, frequency trends differ more than those within the two historical periods which, according to Green, may be due to a short time frame like Great Vowel Shift (145). A problematic issue in dialect analysis is the limited dialect types since the Old English period of the corpus is nearly a collection of West Saxon.

Chapter 6 turns to the notion of coherence and cohesion, exploring in more depth how they work together with the Adaptive Approach to Grammar and English clause combination. The analysis finds a level of complementary distribution between clause combination in English and explicit cohesive ties such as those identified by Halliday & Hasan (Reference Halliday and Hasan1976). Therefore, it provides further evidence to support the Adaptive Approach’s conception of grammar as a coherence coding system in speakers’ repertoire of their language, rather than a set of independent rules, which is conducive to processing various relationships in discourse.

Chapter 7 presents the final study of the book, focusing on one of the claims of the Adaptive Approach to Grammar, i.e. isomorphism between synchronic and diachronic patterns. Using corpus data, especially Treebanks developed over the past decade, Green evaluates the evidence for the theoretical claim regarding an elementary pattern of isomorphism in clause combination in three language areas: spoken and written language, language acquisition and development, and isomorphism across different historical periods (170). The study indicates that less integrated clauses on the hierarchy decline while more integrated clauses develop in the opposite direction. On the other hand, simple cohesive ties exhibit a declining trend as age increases and as they move from spoken to written language. Therefore, we can find an overall increase of integrated clauses in the three areas, which indicates that clause combination moves from simpler coherence to more abstract coherence. Thus, the study offers empirical evidence once again to support the Adaptive Approach to Grammar and its theoretical claim of the relationship between cognition and clause combination.

Finally, Chapter 8 concludes the book with a comprehensive summary of the research findings in the preceding chapters and draws conclusions produced by each of the studies. Green provides the overall conclusion that clause hierarchy is an important feature of what speakers of English know about their language, and its patterns and development are largely consistent with the expectancies of the Adaptive Approach to Grammar. At the end of the book, Green considers some remaining challenging issues concerning the Adaptive Approach, as well as some general limitations of the book as a whole.

Readers, particularly established researchers in this area, will find limitations in some individual chapters, including the lack of strong evidence that clauses higher on the hierarchy tend to maintain temporal continuity across the propositions in the combined constituents in Chapter 2, the lack of a specific code in the Penn Treebank tag-set to guarantee the complete accuracy of the frequency counts in Chapter 4, and the lack of large-scale cross-linguistic Treebanks to expand the span of investigation in Chapter 5. Furthermore, I found only a few spelling errors during my reading of the book but they will probably not constitute serious obstacles for readers. Despite the minor imperfections, the studies in this book justify the proposals of the Adaptive Approach to Grammar, which is therefore a defensible framework for understanding many of the patterns of the English clause system.

Taken as a whole, this impressive and appealing volume presents an overview of the features and functions of clause combination. On the one hand, the book is composed of self-contained chapters, each having its own focus, and readers could read them independently according to their own need and interest without the worry of losing comprehensibility. On the other hand, however, each study builds upon the others with the framework of the Adaptive Approach to Grammar running through them and they work together toward the overall goal of understanding the English clause system and its patterns and development, as well as the relationship between the clause system and cognition. As a substantially-grounded and empirically-supported book, it covers issues ranging from describing the clause system as a hierarchy both in the contemporary English language and its historical development, to exploring its interaction in corpora with discourse coherence. This work contributes to the innovative interdisciplinary work between corpus linguistics and cognitive-functional linguistics. It works well as a reference book for scholars of linguistics and cognition. It will open up new dimensions particularly for teachers of English as a foreign (second) language, give them a deeper understanding of the clause system, and provide helpful suggestions for students as well.