A cross-linguistic study of negation in English, French, and Korean examined the relationship of transparency and position of marker to acquisition of negation. Data were drawn from a longitudinal study of nine children: two native Korean-speakers, two American speakers of English, and five speakers of French. Five of the children were studied for over a year. Mean length of utterance (MLU) in recorded spontaneous speech and age were independent variables measured. The negative forms differ in each language in their transparency between form and meaning, and it was predicted that French-speakers would acquire their more transparent forms first. It was found that all the children began to combine negative markers with other lexical items at a MLU of 1.4-1.5, but that French-speakers acquired it earliest in terms of MLU and age. Variation was found in the acquisition of different negative forms within each language. The results also indicate that all the children preferred preposing the negative form at the early stages of acquisition, contradicting some earlier research. (MSE)