English language corpora, containing the widest possible range of varieties of English, provide empirical date concerning language usage, helping to redefine the notion of "standard" to which language learners should aspire. This paper takes as its theoretical framework an approach to corpus-aided discovery learning in which the central role of corpora is seen as that of providing rich sources of autonomous learning activities. Here, by investigating Chinese EFL learners' use of the infinitive "to" in the Chinese Learner English Corpus (CLEC), the suggestion is put forward that availability of different corpora and software tools and the ability to combine them in different ways may help learners develop an understanding of the patterned quality language and be conducive to more appropriate use, as learners are not just to observe patterns, but also to develop hypotheses as to their variability. Finally, a corpus-aided approach is proposed to provide insight into new perspectives to revolutionize EFL instruction.