Little attention has been paid to the question about generality versus modularity of the learning potential (LP). The main research question of our study was: Is the students' LP established with the help of a dynamic assessment of their English as a foreign language (EFL) oral proficiency general enough to predict their subsequent EFL reading and writing scores? Eighty students (38 boys, 42 girls) received a dynamic assessment of their EFL oral proficiency in a pretest -- mediation -- posttest format. Six months later they took a standard EFL reading comprehension and writing exam. The results indicate that the correlations between oral LP scores and both reading (r = 0.42) and writing (r = 0.45) are significant and much stronger than the correlations with the static oral pretest. Oral LP appears to be general enough to predict students' subsequent reading and writing achievements.