This study investigates the extent to which paper-based data-driven learning (DDL) activities can improve Thai EFL students' grammar learning of conditional sentences (the second condition), as well as the participants' attitudes toward learning through the DDL approach. This was a two-week research using a one-group pre-test and post-test design. The convenience-sampled participants were 15 Thai EFL undergraduate students majoring in English at the Faculty of Humanities and Social Sciences. This study included three research instruments: a pre/post-test, an attitudes questionnaire, and interviews. The instructional approach, which consisted of the paper-based DDL material, was devised using The Corpus of Contemporary American English (COCA) consisting of 40 concordances. Using non-parametric statistics Wilcoxon Signed Rank Test, there is a statistically significant difference in mean scores in the findings (p<0.001), indicating that their grammatical knowledge was developed after participating in DDL activities. Furthermore, the participants had positive attitudes towards DDL learning since they considered DDL as a fruitful and beneficial tool in helping them acquire grammatical knowledge and language patterns by themselves. Therefore, the outcomes of the research have a noteworthy impact on the field of teaching English, showcasing the potential of utilizing corpus data to analyze genuine language patterns and enhance learners' understanding of language structure.