The degree to which native and non-native readers interpret English sentences incrementally was investigated by examining plausibility effects on reanalysis processes. Experiment 1 required participants to read sentences word by word and to make on-line plausibility judgements. The results showed that natives and non-natives immediately computed the plausibility of the preferred structural analysis, which then affected ease of reanalysis. Experiment 2 required participants to read the same sentences word by word in order to perform a memory task. The natives showed a similar pattern of results to Experiment 1, whereas for the non-natives plausibility effects were delayed. However, the non-natives still appeared to be performing immediate syntactic reanalysis. It is concluded that syntactic processing was person- and task-independent, whereas the incrementality of interpretation was more dependent on task demands for the non-natives than for the natives.