Intonational development has been an area of interest during the past four decades, from the perspectives of both production and perception. But relatively few conclusions have been made about how children acquire the intonational component of their grammar. To date, prior studies of intonational development have not included a fine-grained pragmatic analysis of the types of intentions that may be encoded intonationally in a given language. This dissertation takes an integrated approach to the study of intonational development within the domain of yes-no questions, looking at the specific case of Puerto Rican Spanish (PRS). I provide evidence from production and perception for three phonological contours used for yes-no questions adult PRS: a default contour that encodes interrogativity, and two specialized contours that encode epistemic information in addition to interrogativity. Production results from two longitudinal corpora for two female PRS-acquiring toddlers between the ages of 19 and 43 months showed that the epistemic contours are infrequent in both Child Directed Speech (CDS) and child speech, though caretakers do have CDS-specific uses of the epistemic contours. Children produced the default contour almost categorically, though some evidence of epistemic use of intonation appeared around 33 months. A linguistic comprehension task revealed that children were able to perceive distinctions in epistemicity between intonation contours by age 4 and 5, around the same time they have been shown to comprehend other epistemic distinctions. 6-year-olds were more sophisticated in their comprehension. The results presented in this dissertation highlight how important it is to clearly define the form-meaning relationships in the adult intonational system if we are to fully understand how intonation will be developed in child speech. The function of the intonational form is key in understanding when it will be produced and comprehended. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]