Experimental studies regularly find that extraction out of an embedded clause (“long-distance extraction”) results in a substantial degradation in acceptability but that the degradation is much greater when the embedded clause is an island structure. We explore these two facts by means of a series of acceptability experiments with L1 and L2 speakers of English. We find that the L2 speakers show greater degradation than L1 speakers for extraction out of non-islands, even though the two groups behave very similarly for extraction out of islands. Moreover, the L2 degradation with non-islands becomes smaller and more L1-like as exposure to the language increases. These initially surprising findings make sense if we assume that speakers must actively construct environments in which extraction out of embedded clauses is possible and that learning how to do this takes time. Evidence for this view comes from cross-linguistic variation in long-distance extraction, long-distance extraction in child English, and lexical restrictions on long-distance extraction. At a broader level, our results suggest that long-distance extraction does not come “for free” once speakers have acquired embedded clauses and extraction.