Are lexical frequency effects similar across grammatical domains? How does the strength of frequency effects compare to that of other constraints on variation? Has the role of frequency been exaggerated? This study addresses these questions by examining lexical frequency in two variable phenomena in Spanish: (1) coda /s/ weakening and (2) subject pronoun use. Multivariate analysis indicates that lexical frequency shapes patterns of variation in both variables. However, while frequency effects are comparable in terms of strength -- statistically significant for each variable but weakly predictive compared to other factors -- the nature of the effects is different. Higher frequency promotes increased similarity in the phonetic domain but increased differentiation in the morphosyntactic domain. These results support a conservative position, one that acknowledges the capacity of lexical frequency to shape patterns of linguistic variation while also recognizing its explanatory limits and resistance to generalization across different levels of grammatical structure.
