Research indicates that mothers scaffold the literacy skills of their children when jointly engaged in literacy-related activities in monolingual families (Tamis-LeMonda et al., 2001). Yet little is known about the linguistic environment of English language learners in the USA, a group at high risk for reading difficulties if they are only taught in English and the school is not mindful of their linguistic and cultural strengths (Snow et al., 1998). We studied mother-child language interactions in Spanish-speaking families in the USA during two literacy-related activities at home (book reading and a homework-like task). We employed language data analysis, discourse analysis, surveys and observations to study four cases of mother-child communication and its relation to the children's literacy and language skills (letter-word identification, dictation, vocabulary). Mother-child proficiency in the same language (Spanish, English or bilingual similarities between mother and child) was necessary, but not sufficient, to facilitate their communication. Maternal language and literacy skills in this sample related to the quality of language input, but only in dyads with shared language did it relate to successful communication and the child' skills. Continuity between home/school language and literacy showed compounded support for language that transferred to literacy skills across languages. This association was observed even in dyads with mothers who had scored low on receptive vocabulary or/and had only a few years of formal education. These findings suggest that maintaining a school language environment that preserves mother-child communication and its positive association with learning would yield the best educational outcomes for this particular population. (Contains 3 tables.)