This study explores whether American Sign Language (ASL) users exhibit frequency effects on two-sign combinations as observed in spoken languages. Studies on spoken languages have demonstrated that frequency of usage influences the emergence of grammatical constructions; however, there has been less investigation of this question for signed languages. To examine frequency effects in ASL, this study analyzes patterns of a grammatical manual negation morpheme glossed as NOT produced sequentially with other signs. Findings reveal that NOT is produced with specific signs, demonstrating that the grammaticalization of NOT increases as frequency does in ASL collocations. The analysis shows that a few signs are highly phonologically fused with the negation marker, providing emerging evidence that these collocations have experienced chunking, as they are schematic, fused constituent structures in ASL. Given frequency effects found in the study, chunking appears to be a domain-general cognitive processing mechanism independent of modality effects.