Suspended affixation (SA) allows a suffix on one conjunct to scope over all coordinated elements. While inflectional SA is productive in Turkish, derivational SA is claimed to be highly restricted; yet speakers readily accept certain cases. We propose that this gradient acceptability reflects a frequency-modulated choice between two possible syntactic representations: base-generation, which licenses derivational SA, and ellipsis. To test this, we conducted a rating task on the acceptability of four derivational suffixes in SA form while manipulating the frequency of coordinations. Using a Multinomial Processing Tree model to isolate latent structural choices from surface ratings, we found that frequency modulated SA acceptability for some suffixes (i.e., sIz ’-less’ and cI ’-maker’), but not others (i.e., lI ’-having’ and lIk ’-for’). These findings suggest that frequency shapes syntactic parsing in morphologically complex environments.

Many gradable properties have been found to be encoded as axes in embedding space. Most commonly, property axes are computed using seed words, but recent work has noted limitations to seed-based axes. Here, we present a novel methodology for computing property axes that is based on human ratings and does not require seeds. We apply this methodology to a particular problem at the syntax-semantics interface: which semantic properties of intransitive verbs affect their likelihood to occur in one of two syntactic structures, unergative and unaccusative. Comparing property axes that encode different semantic dimensions of the concept of agentivity, we find that properties like movement and being alive are a better predictor of the syntactic behavior of intransitives than goal-directedness or intentionality. We discuss the potential of rating-based axes for future work in semantics and at the syntax-semantics interface.

Agreement attraction errors, in which a verb erroneously agrees with an intervening noun rather than its grammatical head, are amplified by morphological syncretism in some languages (English, German, Russian) but not others (Turkish, Armenian), a cross-linguistic pattern without a principled account. We use surprisal and attention entropy from large language models as processing proxies to investigate this variation across four languages. LLM-derived measures replicate behavioral findings in English and German (syncretism modulates attraction), align with Turkish null results (no modulation), and partially capture Russian patterns. We discuss further directions for better understanding why syncretism affects agreement attraction differently across languages.