Researchers from the Technical University of Denmark say that parents should correct their toddlers' mistakes when pronouncing a word since they are unable to realize that they are making a mistake until the age of four.
The researchers conducted the study on adults, two year olds and four year olds by making them listen to a recording of themselves saying "bad" even when they were saying "bed".
While the adults and the four-year-olds tried to correct their presumed mistake by pronouncing it similar to "bid", the two-year-olds continued to stick to their original pronouncement.
In their report, published in the journal Current Biology, the researchers suggested that the toddlers were unable to recognize any mistakes they make in pronouncing and depend on adults to correct their mistakes. "In our study, we found that four-year-olds monitor their own speech in the same way as adults. Surprisingly, two-year-olds do not", the researchers wrote.