Allophones are the sounds that are actually pronounced.
Of course, children are not explicitly told what are the phonemes of the language. Children are left with the task of figuring out the set of phonemes and pronunciation rules. Researchers do not yet agree on how children achieve this task so easily, but there are well established methods that linguists have used to analyze the phonological system of unfamiliar languages, and similar strategies may be useful to children in analyzing their own input. How to identify phonemes, allophones etc. If this is true, then we should expect to find minimal pairs - pairs of words which are identical , except for the two sounds that we are contrasting.