This study explores different frequency effects on children's interpretations of novel noun-noun compounds (e.g. "egg bag" as "bag FOR eggs"). We investigated whether four- to five-year-olds and adults use their knowledge of related compounds and their modifier-head relations (e.g. "sandwich bag (FOR)" or "egg white (PART-OF)") when explaining the meaning of novel compounds and/or whether they are affected by overall frequency of modifier-head relations in their vocabulary. Children's interpretations were affected by their experience with relations in compounds with the same head, but not by overall relation frequency. Adults' interpretations were affected by their experience with relations in compounds with the same modifier, suggesting that children and adults use similar but different knowledge to interpret compounds. Furthermore, only children's interpretations revealed an overuse of visually perceivable relations.