Usage-based models claim that first language learning is based on the frequency-based analysis of memorised phrases. It is not clear though, whether adult second language learning works in the same way. It has been claimed that non-native language lacks idiomatic formulas, suggesting that learners neglect phrases, focusing instead on orthographic words. While a number of studies challenge the claim that non-native language lacks formulaicity, these studies have two important shortcomings: they fail to take account of appropriate frequency information and they pool the writing of different learners in ways that may mask individual differences. Using methodologies which avoid these problems, this study found that non-native writers rely heavily on high-frequency collocations, but that they underuse less frequent, strongly associated collocations (items which are probably highly salient for native speakers). These findings are consistent with usage-based models of acquisition while accounting for the impression that non-native writing lacks idiomatic phraseology.