This study reported the development and initial validation of the Survey of Parent/Provider Expectations and Knowledge (SPEAK), a self-administered questionnaire assessing expectations and knowledge about early childhood cognitive and language development. Development of the SPEAK was guided by the theory emphasizing the role of language input quality in young children's language development. Items were refined through cognitive interviews (N = 29), expert consultations, and the first field test (N = 131). Rasch analysis following the second field test (N = 346) resulted in a 17-item SPEAK (a = 0.84); expert review confirmed its content validity. A third field test with low-income caregivers (N = 103) showed that higher SPEAK scores were correlated with higher education, receptive language ability, stronger endorsement of incremental mindset, and more language stimulation available to the child at home, supporting its concurrent validity. Findings provided preliminary evidence supporting the reliability and validity of the SPEAK to assess expectations and knowledge of early childhood cognitive and language development.