Due to both experimental and theoretical controversies on semantic relatedness research in second/foreign language (L2) education, the present study provides an alternative approach by investigating English-as-a-foreign-language (EFL) learners’ cognitive processing of semantically related and unrelated words. The participants were 38 Iranian EFL learners from upper intermediate classes at a private language teaching school. Employing a semantic priming experiment, the EFL learners saw a pair of words, and were asked to decide whether or not the target word (i.e. an adjective) was related in meaning to the preceding word (i.e. a noun). A two-way Repeated Measure ANOVA was run on reaction time (RT) and error rate (ER) data. Results of the study showed that semantically related words induced faster RTs than semantically unrelated ones, confirming the positive effect of the semantic relatedness in cognitive processing of L2 words. However, higher ERs in related conditions in comparison to unrelated conditions refer to a kind of confusion on the part of EFL learners.
