Spellout

Spell-Out is a technical term in modern syntactic theory that refers to the process by which a completed syntactic object is transferred from narrow syntax to the two interface systems of language: phonology (PF) and interpretation (LF). In Minimalist and Phase theory, derivations unfold in a sequence of phases, typically vP and CP. When a phase completes, its contents are spelled out to PF and LF, and elements not spelled out become inaccessible to higher parts of the computation due to the Phase Impenetrability Condition (PIC).

What is spelled out includes the elements of the phase that are visible at the edge and any material that is lexically realized during Spell-Out; the rest remains in the current workspace until later phases. Substantial operations, like movement or agreement, are constrained by Spell-Out: the next phase can only access the phase's edge and any features transferred through Spell-Out. This cyclic spelling-out helps explain successive cyclic movement patterns and the locality of dependency formation.

In practice, Spell-Out is a theoretical mechanism rather than a directly observable phenomenon. It is often described as the moment when syntactic structure is converted into phonological form (how words are pronounced) and into a format compatible with semantic interpretation. Some frameworks posit distinct Spell-Out stages for PF and LF, while others treat the process as a single transfer to both interfaces.