This paper explored a less-studied preposition, "after," and its uses in a corpus. The analysis included an inspection of dictionary senses, followed by the distributional patterns of parts-of-speech, the co-appearing verbs of "after," the contextual uses of [-"ly after"] and [-"ly after"+NOUN], and finally a pre- and post-teaching investigating the effectiveness of using a corpus. The goal was to see what semantic information is embedded in "after" in each of these analyses and to explain the contextual uses of "after" that are not often realized. We used probes and corpus techniques to search for instances in the British National Corpus to retrieve expressions of "after" that appear in certain contexts. Based on the data, two conceptualizations of "after," comprising the relations of two events, were postulated. For the uses of "after" and its two constructions [-"ly after"] and [-"ly after"+NOUN], we also tested their production by EFL students before and after a corpus workshop was introduced to EFL learners. The results showed that the workshop not only was effective, but also helped accelerate students' speed of generating expressions of "after." This paper could serve as a sample work for research on function words, and it also imposes pedagogical implications on the effectiveness of using a corpus for EFL learners.