and English Language, University
of parallel and successive operations is what builds complexity.
Carroll, Endless forms most beautiful, ch. 4
the publication of , this page
presents a selection of my writings, arranged so as to provide a general
survey of Stratal OT. The page describes the main features of the theory as
I currently understand it myself; other scholars pursuing similar
lines of inquiry will no doubt disagree with me frequently on matters of
detail, and occasionally on matters of principle. I focus on the
leading ideas and major architectural assumptions of Stratal OT, and
empirical results that follow directly from them; work on the detailed implementation of the theory
||Those looking for a brief schedule of readings covering the essentials of Stratal OT may wish to work through items , , , , and , in that order.
was created on 11 December 2010. It was initially based on the
syllabus of a course on
phonological cycle’ which I taught at the 2010
LOT Summer School in Nijmegen; I am grateful to the organizers
of the LOT Summer School and to the students on the course for that
invaluable opportunity to clarify and develop my thought on Stratal
was last updated on 31 October 2017.
OT arises from the combination of three powerful ideas, each with a
long and complex intellectual history of its own:
phonological cycle, which dates back to the earliest days
of generative phonology;
stratification, which has roots in the Prague School distinction between
phonologie du mot and phonologie de la phrase,
but is most closely associated with Lexical Phonology;
constraint-based computation in the manner of OT.
combined, these elements react with one another in interesting ways:
Replacing the ordered rules of Lexical Phonology with the ranked
constraints of OT strengthens the concept of cyclic
domain: see , ,
Adopting a stratal-cyclic architecture for phonology enables one to dispense with
many of the constraint types and correspondence relations posited in mainstream
OT: see , , and below.
A stratal-cyclic architecture also allows one to restore a modular and
local conception of
the morphosyntax-phonology interface within OT: see ,
, , and below.
hypothesis of the phonological cycle  asserts that certain constituents in the morphosyntactic structure of a linguistic
expression define domains for phonological computation. Phonology applies iteratively over these domains,
starting with the smallest, least inclusive cyclic domains, and
moving progressively outwards to larger, more inclusive cyclic
and  I provide arguments for a cyclic approach to
morphosyntactic conditioning in phonology and against output-output
correspondence. The cycle is shown to make several correct
predictions, including the following, which is a corollary of the Russian
If a phonological process exhibits cyclic misapplication within a certain phonological configuration created by affixation, then it must also exhibit cyclic misapplication if the same configuration arises by word concatenation.
the version of Stratal OT that I currently envisage, the
phonological cycle is an emergent
phenomenon, and cyclic effects within stem-level
domains have a particular aetiology: see  and .
hypothesis of phonological stratification  asserts that, for the purposes of phonological interpretation, morphosyntactic
constituents are divided into
three types: stem-level, word-level,
and phrase-level. Each type is associated with its own
ranking of phonological constraints.
stratification enables one to state systematic
correspondences between morphosyntactic constituents and cyclic
domains: see  and .
highest node in a linguistic expression triggers a cycle of the
inflectionally complete grammatical word triggers a cycle of the
created by root-to-stem derivation, and by an idiosyncratic set
of derivational (stem-to-stem) and inflectional processes, trigger cycles of the
stem-level phonology. However, internal cyclic effects within stem-level
domains exhibit irregularities as part of the stem-level
do not trigger cycles.
regard it as a long-term goal of the theory to account for the emergence
of these correspondences: see  and 
for some steps in this
OT does not impose formal limits on the extent to which constraint
rankings may differ across levels within the grammar of a single
language. Rather, the life cycle of phonological processes keeps level divergence at bay
through diachronic change: see , ,
and  for discussion
of this point.
as I envisage it acknowledges the fact that word-level affixes can
and do occur inside stem-level affixes; but it nonetheless upholds
the claim that word-level phonological cycles never precede stem-level cycles.
Take, for example, English devélop
~ devélop-ment ~ devèlop-mént-al. The stem-level
suffix -al attaches outside word-level -ment.
base of -al is a stem rather than an inflectionally complete
grammatical word (cf. *development-s-al), and it therefore does
not trigger a word-level cycle: see .
OT assumes that, in each phonological cycle, the mapping from input
to output is effected by means of parallel constraint-based
computation in the manner of OT.
Stratal OT disavows many features of mainstream OT:
Stratal OT rejects many of
the constraint types and correspondence relationships to which mainstream OT
resorts when dealing with
morphosyntactic conditioning effects. Notably, there are no output-output
identity constraints: see  and .
line with its modular approach to the
Stratal OT imposes strict limits on the ability of phonological
constraints to refer to extraphonological information: e.g.
lexically indexed constraints are banned .
emphasis on cyclic locality reverses
classical OT's trend towards excessively global analyses: see , , and .
OT vs Lexical Phonology
Although Stratal OT
draws heavily on the tradition of Lexical Phonology, the two
frameworks differ in important respects:
possible to turn a Lexical Phonology analysis into a Stratal OT
one simply by replacing the ordered rewrite rules of the former
with the optimality-theoretic constraints of the latter. Principles such as Strict
Cyclicity and Structure Preservation play no role in Stratal OT;
and, unlike Lexical Phonology, Stratal OT bans devices such as
the extrinsic ordering of segmental transformations before
prosodification within a cycle. In consequence, the concept of cyclic
domain has far greater empirical content in Stratal OT than
in Lexical Phonology: see  and .
Stratal OT need not
assert that the stratal-cyclic architecture of phonology is
specified innately by Universal Grammar. On the contrary, in the version of the
theory that I currently envisage, stratification and cyclicity emerge from
fundamental storage and processing mechanisms, and from timing effects in the
child’s linguistic development: see 
, , and 
together provide an overall
the place of phonology in the
architecture of grammar, and of the interactions of phonology with the
lexicon, morphosyntax, and
classical modular feedforward architecture
OT assumes a classical modular feedforward architecture of
see  and . In a grammatical architecture of
morphology, phonology, and phonetics constitute separate modules,
each possessing its own proprietary set of representations:
morphology performs computations over morphs;
phonology performs computations
discrete phonological categories;
phonetics performs computations over continuous
articulatory and auditory parameters.
These three modules interact
serially: morphology precedes phonology within each cycle; all phonology
precedes all phonetics;
morphology and phonetics do not share an interface.
and the lexicon
 and  distinguish between two types of lexical listing: complex
constructs may be
listed nonanalytically (as whole output forms) or
listed analytically (as concatenations
of input pieces).
stem-level constructs are
listed nonanalytically, whereas word-level constructs are either
unlisted or listed analytically. This postulate explains the
 and  demonstrate that, in a stratal-cyclic
architecture, the size of lexically listed exponents makes precise
predictions about locality conditions on phonologically driven
allomorph selection. The evidence of allomorphic locality
supports an approach to morphology that is stem-driven,
rather than root-driven.  and  describe
the format of lexical entries in this framework.
 lays out a system of four hypotheses
regulating the modular interaction
between morphology and phonology: the
Four-Hypothesis Programme. This consists of the following four postulates:
Morph Integrity Hypothesis asserts that morphology selects and
inserts morphs as integral units, and does not have the power to operate directly upon
elements of phonological representation such as features, segments, nodes, or
Indirect Reference Hypothesis asserts that phonological constraints other than those on prosodic
alignment cannot refer to morphosyntactic information.
Phonetic Interpretability Hypothesis asserts that output phonological representations do not contain diacritics of morphosyntactic
noted above, the Cycle Hypothesis asserts
that phonology applies cyclically over morphosyntactically
Four-Hypothesis Programme entails an approach to nonconcatenative
morphology labelled Generalized Nonlinear Affixation. In this
view, the role of morphology in apparently
nonconcatenative exponence reduces to the insertion of morphs whose
phonological content is nonsegmental: i.e. floating pieces of
feature geometry or bare fragments of prosody. Item  works out the implications of Generalized Nonlinear Affixation for
the analysis of reduplication. Item 
provides a list of references to recent work in Generalized
Moreover, the cycle
gives rise to a range of locality effects. Items  and  explore cyclic locality constraints on phonologically driven
In addition, the depth of morphosyntactic information
that phonology can access within a cyclic domain is restricted by Phonetic Interpretability:
thus, a form of ‘Bracket
Erasure’ emerges for free, as shown in .
and  address the phonology-phonetics interface:
they provide arguments in favour of the classical hypothesis that
gradient processes of phonetic implementation
may not directly refer to lexical or morphological information. 
and  list a number of phenomena that may create the appearance of
direct morphological conditioning in phonetics. 
discuss the diachronic processes of stabilization whereby gradient
phonetic rules become categorical.
life cycle of phonological processes
in the tradition of Lexical Phonology
and Stratal OT pays close attention to the intimate connection
between the architecture of phonology and phonological change. In
particular, Stratal OT provides an insightful account of the life cycle of phonological
processes, surveyed in , ,
phonetic effects become phonologized as
language-specific gradient processes of phonetic implementation:
processes of phonetic implementation become stabilized as
categorical phonological processes applying across the board in
operating by input restructuring, phonological processes undergo
domain narrowing, and so phonological generalizations
climb up from the phrase level to the word level and from the
word level to the stem level: see  and
, with further examples in 
rules eventually become morphologized or lexicalized:
Each of the steps in
this pathway may produce rule scattering, whereby an
innovative avatar of an existing process enters a higher
component of the grammar whilst the old process remains in
situ: see ,
OT has implications for virtually every area of phonological
research. The basic principles of the theory produce desirable
outcomes when applied to a wide range of problems:
effects vs prosodic effects,
list is far from exhaustive.
there is a broad consensus on the intensional definition of
phonological opacity, the extension of the concept is currently
because a phonological generalization can be classified as opaque or
transparent only against a complex and usually disputed background
of assumptions concerning the theory of representations, the constraint set, the
contents of the lexicon, the role of morphosyntax, the role of
phonetics, and the relative scope of synchronic and diachronic explanation:
see  and . Accordingly, Stratal OT does not
set out to provide a comprehensive theory of opacity; no such theory exists at present, nor is one likely to come within our grasp
in the near future.
OT does, however, make an important contribution in this area: a
stratal-cyclic analysis of a misapplication effect arising from
affixation or word concatenation automatically generalizes to
instances of the same misapplication effect in morph-internal
environments.  highlights the learnability advantages of
effects vs prosodic effects
of the toughest problems in the analysis of morphosyntactically
conditioned phonological phenomena is how to distinguish between the
effects of morphosyntax on phonological representations (prosody) and
the effects of morphosyntax on phonological derivations (morphosyntactically
Stratal OT enjoys significant strengths in this area because if
offers demarcation criteria that are not available to other
is visible to phonetics; cyclic domains are not: see 
domains are exactly coextensive with morphosyntactic
constituents; prosodic units need not be.
effects obey cyclic locality;
prosodic effects do not.
illustrates the advantages of these criteria with an extended
case-study; see also .
classical OT under Richness of the Base, all levels of phonological
representation mix contrastive and predictable information.
This can cause ranking paradoxes when phonological processes apply
in a non-structure-preserving way: i.e. when tokens of a segment x
arise predictably in some environment through allophony or
neutralization, but x never occurs contrastively elsewhere.
In such cases, classical OT may encounter a ranking paradox: the constraint *[x]
must rank high enough to ban
contrastive tokens of x, but it must simultaneously rank low
enough to enable x to emerge as the
output of allophony or neutralization.
OT does not face this problem because segments excluded from the
phonemic inventory of a language are filtered out by the stem-level
hierarchy, but may be permitted to arise again through allophony or
neutralization at the
word or phrase levels: see .
phonological processes typically exhibit a cluster of characteristic
properties, discussed in :
processes may or may not display cyclic reapplication within
complex stem-level forms;
processes may be neutralizing or purely allophonic within
a stem-level process does display cyclic reapplication within
complex stem-level forms, then it cannot be purely allophonic in
minimal domains (Chung's Generalization);
turn, cyclic reapplication within stem-level forms shows
irregularities and exceptions of its own.
and  show that this syndrome can be explained on the assumption that
stem-level constructs are listed nonanalytically.
OT with stochastic ranking retains Gregory Guy's insights into the
effect of cyclicity on phonological variation.
t-deletion applies with greater frequency in mist
(where the [t] belongs to the stem) than in miss-ed (where
the [t] belongs to a word-level suffix) because mist meets the
conditions for t-deletion both at the stem and at the word
levels, whereas miss-ed only meets them at the word level:
OT enjoys privileged insight into those phenomena reflecting the
diachronic life cycle of phonological processes.
allophony of liquids in present-day English provides a good example.
Synchronic phonological processes reflecting early changes in a
diachronic trajectory of liquid lenition tend to apply in smaller
cyclic domains (at higher levels) than processes reflecting later
changes: , . For example, there are many English dialects in which
• r-lenition applies at the word level, and r-deletion
at the phrase level;
• l-darkening applies at the word level, and l-vocalization at the phrase level.
enables us to provide cogent answers to questions such as the rise
of r-intrusion  and the history of English phrasal
addition, Stratal OT illuminates the problems of lexical diffusion,
e.g.  and ,
and of secondary split .
Ricardo. 1999. Constraint
interaction in language change: quantity in English and Germanic
[Opacity and globality in phonological change]. PhD
dissertation: University of Manchester & Universidad de
Santiago de Compostela.
acquisition of phonological opacity. In Jennifer Spenader,
Anders Eriksson & Östen Dahl (eds), Variation within
Optimality Theory: Proceedings of the Stockholm Workshop on `Variation within Optimality
Theory´, 25-36. Stockholm:
Department of Linguistics, Stockholm University. [For an update of my analysis of
Canadian Raising, see here]
Ricardo. 2007. Diachronic
phonology. In Paul de Lacy (ed.), The Cambridge handbook
of phonology, 497-517. Cambridge: Cambridge University
Ricardo. 2007. Morphological
structure and phonological domains in Spanish denominal
derivation. In Fernando Martínez-Gil & Sonia Colina (eds),
Optimality-theoretic studies in Spanish phonology,
278-311. Amsterdam: John Benjamins.
Ricardo. 2007. Marked
phonemes vs marked allophones: segment evaluation in Stratal OT.
Paper presented at the Workshop on Segment Inventories, GLOW
XXX, Tromsø, 11 April 2007.
Ricardo & Ana R. Luís. 2009. Cyclic
domains and prosodic spans in the phonology of European
Portuguese functional morphs. Paper presented at the Old
World Conference in Phonology 6, Edinburgh, 24 January 2009.
Ricardo. 2010. Morphologically
conditioned phonetics? Not proven. Paper presented at On
Linguistic Interfaces II, Belfast, 2 December 2010.
Ricardo. 2011. Cyclicity.
In Marc van Oostendorp, Colin Ewen, Elizabeth Hume & Keren
Rice (eds), The Blackwell companion to phonology, vol. 4,
2019-2048. Malden, MA: Wiley-Blackwell.
Ricardo. 2012. The
architecture of grammar and the division of labour in exponence.
In Jochen Trommer (ed.), The morphology and phonology of
exponence (Oxford Studies in Theoretical Linguistics 41),
8-83. Oxford: Oxford University
Ricardo & Graeme Trousdale. 2012. Cycles
and continua: on unidirectionality and gradualness in language
change. In Terttu Nevalainen and Elizabeth Closs Traugott (eds),
The Oxford handbook of the history of English, 691-720. Oxford: Oxford University
Ricardo. 2013. The stem-level
syndrome. Paper presented to the UPenn Linguistics
Department, Speaker Series, Philadelphia, 11 April 2013.
Ricardo. 2013. The
Spanish lexicon stores stems with theme vowels, not roots with
inflectional class features. Probus 25(1): 3-103.
Ricardo. 2015. Amphichronic
explanation and the life cycle of phonological processes. In
Patrick Honeybone and Joseph C. Salmons (eds), The Oxford
handbook of historical phonology, 374-399. Oxford: Oxford University
2016. We do not need structuralist morphemes, but we do need constituent structure. In Heidi Harley & Daniel Siddiqi (eds), Morphological metatheory,
387-429. Amsterdam: John Benjamins.
Phonology. In S.J. Hannahs & Anna R. K. Bosch (eds), The
Routledge handbook of phonological theory, 100-134. Abingdon:
Ricardo. In preparation. Stratal Optimality Theory
(Oxford Studies in Theoretical Linguistics). Oxford: Oxford
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