Recent theoretical and empirical research has been focused on the exhaustive interpretation of the Hungarian preverbal focus construction. Views are divided if the exhaustivity is determined by a syntactic-semantic operator or if it can be attributed to pragmatic factors. Here, I attempt to test Reinhart’s (2006) Interface Theory of Focus which claims that focus is not syntactically encoded but it is identified at the interface. I conducted two child acquisition experiments since children have limitation of cognitive resources. Therefore, their performance was expected to be affected. It was found that in non-exhaustive context children did almost like adults when interpreting focus constructions with ‘only’ but they had significantly lower adult-like rejection rates in case of preVf. These data indeed suggest that Reinhart’s (2006) theory that focus is coded at the interface is right.