This study aimed to investigate the effect of delexicalisation of common verbs on the collocational competence of Iranian EFL students. It also addressed the effect of proficiency level on their collocational competence. Forty-five English majors with low, intermediate and high proficiency levels at Kashan University participated in this study. To investigate their collocational knowledge, each group received a metalingual judgment test asking them to judge the acceptability of 64 collocations of four common verbs (have, give, take and make) in delexical uses in English. Moreover, think-aloud protocols were collected to assess the validity of the judgment test which revealed different sources of collocational errors made by the participants. The results indicated that not only knowledge of delexicalised collocations tends to fossilize at an intermediate level but it did not increase with proficiency. {\textcopyright} 2011 Published by Elsevier Ltd.