The present study examines the tradeoff between the on-line construction of modifier-noun gender agreement and verb-subject person/number agreement vs. the automatization and entrenchment of agreement, through the study of bilingual speakers of Spanish and the Afro-Colombian creole language Palenquero, whose lexicon is highly cognate with Spanish, but which lacks morphological agreement. The study focuses on first language (L1) Spanish speakers who are acquiring Palenquero as a second language (L2), since when switching from the modifier- and verb-agreeing L1 to the agreement-less L2, the persistence or absence of agreement in cognate items can be taken as an indirect measure of the cost differential between producing morphosyntactic agreement and suppressing the carryover of obligatory agreement to the L2. The results of experiments, which was conducted with bilingual Spanish-Palenquero speakers in San Basilio de Palenque, Colombia, reveal the tenacity of Spanish gender agreement among L2 Palenquero speakers; heritage Palenquero speakers' retention of gender agreement falls between traditional speakers and L2 speakers. Spanish verb agreement, on the other hand, shows relatively little carry-over to Palenquero, suggesting that the suppression of L1 agreement during L2 acquisition is not a simple all-or-nothing matter.