Structural patterns in homesign provide unique insight into the potentially foundational properties of human language. The implications of evidence from homesign, however, can only be understood in light of the observation that homesign is not truly created de novo. Rather, homesigners do have access to the co-speech gesture of the ambient speaking community and this accessible system may influence the development of their idiosyncratic homesign system. Thus, in order to understand homesign and the evolution from homesign to ‘conventionalized’ sign language, it is necessary to understand the properties of co-speech gesture and the structural similarities between sign and gesture. In this talk, I will focus on these two related continua of language development, homesign-sign language and gesture-sign language, and the ways that they suggest we critically (re-)evaluate the relationships between signed and spoken language, sign language and gesture, and gesture and language. In doing so, I will highlight recent research on the expression of number (plurality, pluractionality) and event meaning (transitivity, telicity) in gesture, homesign, and sign language.