This study investigates whether congruency (+/- literal translation equivalent), collocate-node relationship (adjective-noun, verb-noun, phrasal-verb-noun collocations), and word length influence the learning burden of EFL learners' learning collocations at the initial stage of form-meaning mapping. Eighteen collocations were selected on the basis of a pretest. They were divided into 9 congruent and 9 incongruent collocations and into 6 verb-noun collocations, 6 phrasal-verb-noun collocations and 6 adjective-noun collocations. Forty-one EFL learners (first language: Dutch) were asked to read a word list containing the 18 target collocations, their translation and a sample sentence and to complete four online exercises, in which the 18 collocations were presented twice. Learning gains were measured at three levels of sensitivity: form recall test 1, form recall test 2 (+ clue), form recognition test. Although mixed findings were revealed, all factors seemed to affect the learning difficultly of the collocations. Incongruent collocations appeared to be more difficult to recall than congruent ones. Adjective-noun collocations were better recalled and recognized than (phrasal) verb-noun collocations. Depending on the posttest, participants' vocabulary size and word length of the individual constituents making up the collocation also affected the learning process.