From those first baby coos and squawks to the non-stop parade of fully-formed toddler questions, the process of developing language is long and incredibly complex. A recent study uncovered the secret benefit to hearing, but not necessarily learning to speak, a second language as a baby.

Researchers reported in Royal Society Open Science that a group of Dutch speaking adults who were adopted from South Korea before they were old enough to speak had retained latent Korean language skills. Despite never actually learning to speak Korean, the group had absorbed enough from hearing the language as infants that they were able to identify and learn to speak complex Korean sounds that would be difficult to master for anyone other than native Koreans.

Prior to this finding, experts believed that babies didn’t start to learn language until around 8 months, but since the adults studied were adopted before 6 months old, the research suggests that language develops much earlier, possibly even during pregnancy.

Did you talk to your baby when you were pregnant? Share your thoughts on this study in the comments.