This study attempts to determine factors which would predict Spanish ability in experienced bilingual teachers in order to plan language development lessons for prospective bilingual teachers. A review of literature on personality, social, and psychological factors in learning a foreign language suggests that there may be some correlation between these factors and native bilingualism as well. A study was undertaken of experienced teachers in graduate schools of education, all born in the U. S. and raised in Spanish-speaking homes. Tests were administered to assess language ability and personality factors. A discriminant function analysis was conducted to determine which of the 39 scores from these three tests were the most promising. In a second phase of the study, a regression analysis was conducted to measure the effects of the personality variables on the dependent variable of oral Spanish ability. The study was then generalized to a larger population. The results of this part of the study indicate that the findings of the first two phases could not be generalized to the population of native bilingual teachers. However, both studies indicated that formal Spanish courses do not necessarily lead to the development of active and passive language skills. (AMH)