The sentences in texts are far more complex and diverse than those that children commonly encounter in oral language. This raises interesting questions as to whether the understanding of some sentence types might be more important than others in children's reading comprehension. Accordingly, we examined the relation between children's reading comprehension and their understanding of two types of sentences: one we label as basic sentences, which are common in both oral and written language, and the other we label as difficult sentences, which are more restricted to written language. One hundred and four English-speaking students (mean age = 10.8 years) completed an experimental measure of oral sentence comprehension capturing these two sentence types, a standardized measure of reading comprehension, as well as control measures for word reading, phonological awareness, vocabulary and working memory. After accounting for the variance explained by the control measures, hierarchical linear regression analyses revealed that comprehension of basic sentences, but not of difficult sentences, was significantly related to children's reading comprehension. These results demonstrate that, at least in the 5th grade, English-speaking children use their understanding of those sentences for which they have gained a strong foundation through oral language (i.e. basic sentences) to springboard into reading for understanding.