This study describes the use of word recognition strategies by Spanish-English bilingual first graders in their non-instructed language. The behaviors of 35 first graders are described when they were asked to read in the language in which they had not received systematic reading instruction. Seven word recognition strategies used by children when reading in their non-instructed language were identified. The analysis of frequencies of each strategy revealed differences between the two language groups, which can be attributed to differences in the children's language knowledge and different language orthographies. One of the most important conclusions of this study is the finding that children have spontaneous approaches to reading in a language in which they have not been instructed. The study of prior conceptions is a common activity in other educational fields, such as science education, but it is rare in the area of second language acquisition. Following the logic of the emergent literacy field, understanding these preconceptions, whatever their source, is relevant for instruction, either to build on them when they are correct, or to explicitly correct them when they are wrong. (Contains 35 references.) (KFT)