Negation is one of the most important concepts in human language, and yet little is known about children’s ability to comprehend negative sentences. In this experiment, we explore how children’s comprehension of negative sentences changes between 2- to 4-year-old children, as well as how comprehension is influenced by how negative sentences are used. Children between the ages of 2 and 4 years watched a video in which they heard positive and negative sentences. Negative sentences, such as “look at the boy with no apples”, referred either to an absence of a characteristic or an alternative characteristic. Older children showed significant improvements in speed and accuracy of looks to target. Children showed more difficulty when the negative sentence referred to nothing, compared to when it referred to an alternative. In addition, children showed an early tendency to look towards the named noun, even when that noun was negated. This study contributes to our understanding of children’s comprehension of negative sentences, as well as our understanding of the conceptual structure of negation.