This chapter introduces the motivation, scope, and theoretical foundation of the book. It begins by outlining the phenomenon of vowel reduction, in which vowels undergo qualitative or quantitative changes in unstressed positions, and emphasizes its significance for understanding the interaction between phonetics and phonology. To account for this, it proposes Mora Loss and Restoration Theory, which treats vowel reduction as a process triggered by mora loss, potentially leading to further phonetic or featural adjustments. Finally, it discusses the methodology for testing and verifying the theory.

This chapter introduces Mora Loss and Restoration (MLR) Theory, which posits that vowel reduction always involves mora loss. In this process, unstressed vowels lose their moras and function as non-moraic syllable heads. As a result, high and low vowels (e.g. /i, u, a/) become their corresponding glides, while mid vowels (e.g. /e, o/) either centralize to central glides or raise to high glides, depending on the grammatical system. In certain prosodic contexts, unstressed vowels may undergo mora restoration, regaining moraic status. This process is observed in New Zealand English and European Portuguese speakers. Beyond mora loss and mora restoration, MLR identifies various feature change processes that interact with and are influenced by these moraic shifts. One key process is feature loss, where unstressed vowels reduce to schwa. The chapter also explores the implementation of MLR Theory within both rule-based and constraint-based frameworks. Finally, the chapter discusses the phonetic and phonological evidence required to support MLR Theory, highlighting the importance of experimental studies for its validation.

This chapter outlines directions for future research inspired by Mora Loss and Restoration (MLR) Theory. It first reiterates that vowel reduction involves mora loss, followed by optional processes such as feature loss and mora restoration. This approach unifies cross-linguistic patterns observed in languages such as New Zealand English and European Portuguese. While MLR Theory explains how vowels transition to non-moraic glides or schwas, it also calls for further empirical testing through detailed phonetic and phonological analysis. The chapter then extends the framework to consonants, syllables, and metrical feet. Mora loss may explain degemination in unstressed geminates, contextual weight alternations in codas, and the behavior of syllabic consonants. These predictions invite more data-driven research on how moraicity shapes both vowel and consonant reduction. Finally, the theory opens new avenues for reconsidering traditional metrical structures, particularly how non-moraic syllables challenge established assumptions about foot formation and prosodic hierarchy.

This chapter examines vowel reduction among four European Portuguese speakers, focusing on mora loss and mora restoration as key processes. While traditional descriptions suggest a uniform reduction pattern, this chapter reveals individual variation in how unstressed vowels are realized. Mora loss causes unstressed vowels to lose their moras. High vowels /i/ and /u/ become their non-moraic counterparts, while mid vowels (/e, ɛ, o, ɔ/) may undergo centralization, raising, or even deletion. The low vowel /a/ further undergoes feature loss, reducing to schwa. Additionally, deletion occurs to some speakers, particularly for unstressed high glides. Significantly, some speakers exhibit mora restoration, selectively regaining moras for certain non-moraic heads, leading to diverse reduction patterns. The chapter emphasizes the role of acoustic analysis in uncovering subtle phonetic differences, showing that duration is a key factor in distinguishing moraic from non-moraic heads. The findings highlight the complexity of vowel reduction systems and suggest that phonological theories must account for speaker-specific variation and prosodic influences.

This chapter examines vowel reduction in a New Zealand English speaker, arguing that it involves three independent processes: mora loss, feature loss, and mora restoration. The study challenges traditional accounts by showing that vowel reduction is not merely a feature change but a systematic process affecting moraicity. The speaker’s vowel system shows considerable complexity, with surface schwa types shaped by stress, moraicity, and phonological context. Notably, the speaker distinguishes between super-short, short, and long schwas, with short and long schwas alternating with super-short schwa in unstressed positions. In the speaker’s speech, unstressed vowels first lose their moras and then undergo feature loss, becoming non-moraic schwa. Some vowels undergo mora restoration, regaining moraic status in specific environments. The chapter also examines unstressed vowel alternations, showing that vowel reduction operates differently in lexical and function words. Acoustic data from experiments confirm that duration serves as a key indicator of moraic status. These findings show that vowel reduction results from interacting phonological mechanisms.

This chapter evaluates alternative theories of vowel reduction and contrasts them with Mora Loss and Restoration (MLR) Theory. Some models reject non-moraic syllables, attributing vowel shortening to phonetic effects. Experimental evidence from New Zealand English and European Portuguese shows that durational and phonological differences among reduced vowels cannot be explained by phonetics alone, supporting a moraic distinction between short and super-short vocoids. Sonority-based theories (e.g. de Lacy 2006) treat reduction as avoidance of high-sonority vowels in unstressed positions, but overpredict unattested patterns and fail to capture durational contrasts. By contrast, Crosswhite’s (1999, 2001) contrast-enhancement theory explains reduction as maximizing perceptual distinctiveness, yet cannot account for asymmetrical vowel-raising patterns or cases where unstressed vowels uniformly lower to [a]. Feature-loss-only accounts (e.g. van Oostendorp 1995) recognize centralization but overlook moraic structure as the initial trigger. The chapter argues that MLR Theory best explains vowel reduction, deriving it from mora loss with optional feature loss and mora restoration.

This chapter discusses the externalization path steps that occur after spell-out. Minimalism has created an intermundia, PF, that is no longer syntax but not yet phonology. Pre-minimalism, PF was co-extensive with phonology, but a number of things that were thought to be syntactic in kind but turn out not to be “perfect” are unloaded: this is how copy deletion/deletion of unpronounced elliptic pieces occurs “at PF.” The same for undesirable movement, which is made into PF movement. PF has become phonology + X where X is all those things that need to be unloaded from syntax. I argue such an entity can’t exist because it is a modular monster where syntactic and phonological vocabulary cohabitates, and discuss alternatives to “deletion at PF,” to uphold both minimalist goals and modularity. The chapter evaluates the impact of spell-out on phonological theories of the interface in a phase-based environment. It argues that the workings of the phonology–morpho–syntax interface are also applicable to the interface of phonology with phonetics: post-phonological spell-out transduces the output of phonological computation into phonetic vocabulary through a list-based conversion.

This chapter pursues an interpretation of Chomsky (2021) where phonology and some phonetics are part of I-language. It presents an analysis of Hebrew verbs which addresses issues of linearization from a Strong Minimalist Theory (SMT) perspective. Analogs between how SMT applies to syntax vs. phonology are identified. One main result is that there is no linearization as commonly assumed within the language faculty nor is there likely a strict “beads on a string” linearization in the Sensory Motor module. The chapter builds off of proposals from Raimy (2000, 2003), Idsardi and Raimy (2013), and Papillon (2020), which provide the current best starting point from which to further develop a pursuit of SMT within phonological theory.

This chapter introduces the basics of articulatory phonetics, including place and manner of articulation, voicing, and aspiration, along with the terminology and International Phonetic Alphabet symbols used to describe language sounds. The sounds of Modern Standard Chinese are described and symbolized, along with the tripartite analysis of Chinese syllables into initial, final, and tone. Phonology is introduced first with a discussion of tonal phonology and syllable structure, following by the introduction of the concept of phoneme.

The poverty of the stimulus in the domain of language refers to the gap between the knowledge of grammar attained and the knowledge that could be deduced on the basis of the available linguistic input. Within the Generative Enterprise, the notion of the poverty of the stimulus plays a critical role in the motivation for positing Universal Grammar, a set of innate cognitive principles restricting the range of possible human grammars. This chapter first considers the poverty of the stimulus in the acquisition of native language and then turns to the poverty of the stimulus in the acquisition of nonnative language; both sections review a number of empirical studies documenting language acquisition under conditions of a poverty of the stimulus. For nonnative language, examples are drawn from research on morphosyntax, the syntax-semantics interface, and phonology. These studies reveal that nonnative learners (can) come to acquire subtle linguistic properties which could not be deduced (i) from their native-language grammar, (ii) from the Target Language input available to them or (iii) from classroom instruction.

Before we can talk about how we learn, use, and lose language, we need to define what it is, and what it isn’t. Over the centuries, many people have attempted to describe language. In this chapter was ask: what is language? This is a simple enough question although the answer is much more complicated, and intriguing, than it seems at first. The question of “what is language?” isn’t something we can just sum up in a single pithy sentence. Language is a system of communication, but it’s so much more than that. Language is multi-faceted. It involves signs and symbols, smaller and bigger segments, dialects and accents, and also writing and signing. This chapter serves as a primer to introduce us to the basic underlying principles of language sceince, so we can now talk the talk.

Heritage language speakers are second language (L2) speakers of a sociopolitically majority language. Their native heritage language is a minority language which typically develops under linguistic pressure from the majority L2 and eventually becomes secondary and weaker than the L2. In the past decade, research on heritage language speakers has investigated the degree of acquisition of different aspects of the heritage grammar and how the process and outcome of heritage language acquisition are similar to and different from adult L2 acquisition. Advances in the acquisition of heritage languages have contributed significantly to inform key questions in L2 acquisition. This chapter discusses the latest research on how L2 learners’ and heritage speakers’ exposure and use of the L2 and L1 affect the processing and acquisition the L2 and the heritage language and points to areas in need of further research.

This chapter will introduce the reader to the study of third (L3) or further (Ln) acquisition. The circumstances surrounding the acquisition of language beyond the second conspire to make this a unique context, distinct from L2 acquisition. The L3 learner has at least partial knowledge of more than one grammar, previous experience with nonnative language learning and, in most cases, at least some metalinguistic knowledge. All these factors significantly condition both the starting point and the trajectory of L3/Ln language acquisition in ways that cannot be predicted from our understanding of L1 and L2 acquisition and reflect qualitative as well as quantitative changes in going from two to three or more languages. In this chapter, the reader will find an introduction to the basic concepts and themes of L3/Ln acquisition research, an overview of L3/Ln theories from a cognitive perspective – modeling the acquisition of both morphosyntax and phonology – an in-depth discussion of the role of previously acquired languages, and a brief introduction to some of the most recent work on L3 processing, including studies using electroencephalography (EEG) and semiartificial languages to address long-standing questions in the field while overcoming some of the most common methodological and logistic issues facing the L3/Ln researcher.

An introduction to phonetics and phonology, including discussion of the difference between letters and sounds, an introduction to IPA, articulatory and acoustic phonetics, phonemics and the psychological reality of phonemes, production vs. comprehension and phonemic processes, and phonological word play (spoonerisms, malapropisms, and modegreens).