Focusing on the near-universal verb-noun (or verb-nonverb) distinction in signed languages, I examine whether it is possible to track the development of American Sign Language's (ASL) lexicon. As a first step, I present synchronic and diachronic evidence from ASL noun-verb pairs—signs that are phonologically similar except for movement and carry related nominal and verbal meanings (Supalla & Newport 1987). Specifically, I analyze how many verbs have noun pairs and vice versa, and the lexical effects such as frequency, iconicity, and phonological complexity on their distribution. Using data from ASL-LEX 2.0, a lexicon of approximately 2700 signs (Caselli et al. 2019), I find that only half of verbs have a nominal counterpart, while nearly all of the listed nouns can be traced back to verbal origins. The presence or absence of a corresponding noun is also systematically influenced by lexical effects. This demonstrates that we may try to construct the development of the ASL lexicon with synchronic and diachronic evidence. Most importantly, the results reveal a striking trend: nearly all canonical nouns in ASL originate from verbs, a novel finding with significant implications for our understanding of modality differences, cognition, and language emergence.