Though collocations have drawn much attention in the field of language acquisition, difficulties with them have not been investigated in much detail. This paper reports on a corpus-based exploratory study that analyzes the mistakes learners made when they produced English collocations. The current study shows that not only beginners but also advanced learners have difficulties in choosing the right collocates and the difficulties that learners of different levels have are more or less the same. The L1 influence on the production of L2 collocations exists at every stage of learning though it varies with the learners' L2 competence.
