What is hard to learn is easy to forget: The roles of word concreteness, cognate status, and word frequency in foreign-language vocabulary learning and forgetting

We looked at foreign-language (FL) vocabulary learning and forgetting in experienced FL learners, using a paired-associate training technique in which native-language words were paired with pseudowords. The training involved 6 presentations of the same 60 translation pairs, followed by a test after the 2nd, 4th, and 6th presentation round. A retest followed 1 week after training. The stimulus materials were manipulated on word concreteness, cognate status, and word frequency, and both productive and receptive testing took place. Cognates and Concrete words were easier to learn and less susceptible to forgetting than noncognates and abstract words. Word frequency hardly affected performance. Overall, receptive testing showed better recall than productive testing. Theoretical accounts of these findings are proposed.