[2][3] Functional morphemes encode grammatical meaning within words, but children don't outwardly show their understanding of this.
Recently, linguistics have begun to discover that children do recognize functional morphemes when it was previously thought otherwise.
[1][4] She argues that even though children may not actually produce functional morphemes in speech, they do appear to understand their use within sentences.
Variations of the verb pushes was used and then altered to make nonce words like bazes, pusho, and bazo[1].
The second variation used was the noun phrase the dog which was changed to na dep, or some combination of the correct and incorrect words.
This is thought to be because French has a higher frequency of noun phrases which leads children to pay more attention to functors.
conducted a study on adults who had surgery within six months prior to test for their knowledge of functional morphemes and to determine where in the brain these processes occur.
They observed grey and white matter in the brain and found that the processing of function morphemes occurs in the left temporoparietal junction (TPJ).
[9] They also discovered that if the adult had received damage to their post-superior temporal gyrus (P-STG), then they would have problems producing functional morphemes in the future.
concluded that functional morphemes are required for producing lexically complex words and sentences, and that damage to the P-STG can result in adults having issues with these processes.