An analysis of narratives produced by native and non-native speakers of Spanish shows that they do not differ with respect to the production of "illicit" weak subject pronouns (agreement markers)—null subjects which lead to unresolved ambiguity—in spite of the problems that non-native speakers have with agreement markers and tenses. The production of "illicit" weak subjects is extremely small in all cases and the fact that non-native intermediate speakers use more overt pronouns does not seem to affect the number of "illicit" weak subjects. These data support the conclusions of previous studies where it has been shown that the number of pragmatically deviant ("illicit") weak subjects was not an issue for non-native speakers. It is argued that weak subjects are not problematic for non-native speakers because they are possible due to an unmarked operation of core grammar. These same data also show that native and non-native speakers of Spanish differ in terms of how they resolve ambiguity, since non-native speakers produce significantly fewer instances of weak pronouns (null subjects) with switch reference than native speakers; this is so even though both native and non-native Spanish weak pronouns can bear a [+topic shift] feature.