This chapter provides an overview of phonologically conditioned synchronic alternations representative of Slavic languages. The vocalic processes covered are vowel reduction and resulting phonological neutralization patterns in unstressed syllables, vowel-zero alternations, alternations in vowel quantity due to compensatory lengthening or to rhythmic requirements, and alternations in vowel quality, such as fronting/backing and raising/lowering. The consonantal processes discussed include alternations in voicing, such as voicing assimilation and word-final devoicing, and palatalization before front vowels and as a result of assimilation in a consonant cluster. Some language-specific alternations are also discussed.

The detailed phonology of the word level, defined as the last lexical stratum. This is stratum 2 in English, which, like stratum 1 is word bounded, is structure preserving, and has access to word-internal structure assigned at the same stratum, but unlike stratum 1 is not cyclic and is not subject to the Strict Cycle Condition, allowing rules like Vowel Shift and Velar Softening to apply freely in nonderived contexts. Vowek Shift is a chain shift that affects stressed tense vowels by shifting high vowels to low and raising low vowels to mid and mid vowels to high, without creating any mergers. Some additional rules are required to ensure the final vowel qualities. Some tensing rules apply on stratum 1 or this stratum before Vowel Shift, another applies after Vowel Shift. Vowel reduction produces two or three vowels (depending on dialect), not just schwa as in SPE. Rules for consonants include Velar Softening, Palatalization, Spirantization, with interesting and complex ordering relations. Summary of the stratum 2 rules and their ordering.