This study was undertaken to support the approach of teaching natural language and to illustrate what linguistic research can say to foreign language textbook developers and classroom teachers. The reality of oral conversational Spanish, as illustrated by research in language acquisition, sociolinguistics, and historical linguistics, is one in which the periphrastic future is preferred over the inflected for the expression of the simple future. However, this is not reflected in most texts where it has either been treated as an aside or has been ignored. It is suggested that teachers and textbook/curriculum developers need to examine their instructional goals. If the primary goal is to teach oral communication skills, and if one is committed to a grammatical sequence, students should, at an early age, be formally introduced to the periphrastic future as the most common means of expressing the future in conversation. If one is opposed to using a grammatically based syllabus, students should at least be exposed early in language usage to the more common means of expressing the future. This study illustrates the way a cross-disciplinary approach can identify the most appropriate and useful language for second language learners to acquire. (JK)