This paper examines L2 learners’ familiarity and correct use of formulaic sequences in English. In particular, the extent to which L2 proficiency level and collocational frequency affected L2 learners’ knowledge and use was investigated. Thirty L2 learners of English were tested on their correct use of 32 formulaic sequences in English, made of up ‘Verb + out’ and asked to rate their familiarity with these formulaic sequences. The results showed that the familiarity ratings given by the low L2 proficiency participants showed a significant positive correlation with their accuracy scores, but no such correlation was found for the high proficiency group. Familiarity ratings correlated positively with both word frequency and formulaic sequence frequency, but neither word frequency nor formulaic sequence frequency showed a significant correlation with accuracy of use, although formulaic sequence frequency showed a trend toward a positive correlation. Effects of frequency and decomposability on various types of formulaic sequences are discussed, along with the disparity in L2 learners’ exposure to formulaic sequences and their ability to use them accurately.