Phonotactic constraints describe

• A. Language-specific rules about permissible sound sequences and syllable structures
• B. Word meanings
• C. Spelling conventions
• D. The rhythm of speech

Answer: (A)

Phonotactic constraints describe the allowable sequences of sounds and syllable structures within a language. They are language-specific rules that determine which consonant clusters can occur at word boundaries, which syllables a language permits, and how sounds can combine. This is why the best description is that these constraints govern permissible sound sequences and syllable patterns, not word meanings, spelling conventions, or the rhythm of speech. For example, English allows clusters like str- or pl- at the start and final clusters like -nd or -lk, while languages such as Japanese have simpler CV syllables and fewer permissible consonant clusters, illustrating how phonotactics shape what sound patterns are allowed.