I can understand why the child feels frustrated by this. The child, in this instance, knows what word they are saying and an adult keeps telling the child to say the word they are already saying. The child may feel that they are wrong and/or become discouraged. In the future, I will not pressure young children to say the word as I do. I will, however, continue to expand on what they are saying and repeat what they have said with the correct grammar and word usage. As a child learns speech, they use it for their own purpose, they talk as a way to initiate activity, they verbalize imaginary play, they comment on what they are doing, and they talk to get other peoples cooperation (Britton, Pg. 53). This talk may come out as a "running commentary" from the child as the child is verbalizing their play. This type of speaking is what Vygotsky calls "speech for oneself" which is done as a way to aid their own development and exploration of the world (Britton, Pg. 57). This talk to themselves that children do reminds me of how adults sometimes will talk out loud to themselves as they are trying to figure something out or work out a problem. This talking out of problems sometimes makes it easier understand the problem or why something works the way it does. .
Children in the preoperational stage (according to Piaget) are unable to process logical thoughts and are therefore only able to see the world from their perspective. Children at this stage are egocentric, thus causing Piaget to coin the term "egocentric speech" for this stage of speech development. Egocentric speech happens like running commentary, it is the child's monologue. The child may verbalize what they are doing, as though they have an audience. They speak for the pleasure of speaking, they are playing with speech, and they are figuring things out. This is all done for the child's benefit. .
While children progress through their pre-operational stage of development, their thought processes and speech are becoming more developed.