Abstract: The present study was an attempt to investigate the effectiveness of two types of classroom test practice procedures (individual versus collaborative conditions) on enhancing Iranian intermediate EFL learners’ knowledge of parts of speech. To do so, a quasi-experimental study was carried out, in which sixty Iranian intermediate EFL learners majoring in TEFL were selected as the target participants to serve the purpose and requirements of the study. Their age range was from 19 to 28. To keep the homogeneity of the participants, a proficiency test titled Comprehensive English Language Test (CELT) was given to 92 sophomore students majoring in TEFL, through which sixty were selected based on their scores. The participants were then randomly assigned into two equal comparison groups: The Collaborative Test Practice (CTP = 30) group and the Individual Test Practice (ITP = 30) group. Both the CTP and ITP groups were administered a pretest on vocabulary parts of speech. The two groups then received a ten-session treatment. The participants in the CTP group were involved in collaborative test practice on vocabulary parts of speech while the participants in the other comparison group were exposed to individual test practice condition with the parts of speech. Following the treatment provision, the two comparison groups were administered a posttest which was similar to the pretest except for the rearrangement of some items. The results of paired-samples t-test and independent-samples t-test revealed that both the CTP and ITP groups had vocabulary parts of speech gain but the effectiveness of collaborative test practice techniques on enhancing the participants’ parts of speech in vocabulary was more significant than that of the individual test practice procedures.