The point of departure of this study is the well-known hypothesis according to which structures that involve the syntax-pragmatics interface and instantiate a surface overlap between two languages are more vulnerable to crosslinguistic influence than purely syntactic domains (e.g. Muller and Hulk, 2001). In exploring the validity of this hypothesis for later stages of bilingual acquisition, the study aims to establish whether crosslinguistic influence occur only in one direction, i.e. from English to Greek, which structural factors can account for the directionality of crosslinguistic effects, and whether language dominance plays a role in determining the occurrence and the strength of these effects in older bilingual children. Experimental data are presented from 32 English-Greek eight-year-old simultaneous bilinguals--16 Greek-dominant living in Greece and 16 English-dominant living in the UK--and monolingual control groups. A number of syntax-pragmatics interface and narrow syntax structures were investigated and the results showed that both types of structures were found to be selectively vulnerable to crosslinguistic influence in the predicted direction, but only in the grammar of the English-dominant bilinguals.