What concepts in language development such as telegraphic speech and more is shown when a 3 year old toddler who knows how to talk and form sentences starts to mimick and talk like his baby brother when he notices the baby getting attention. When told to use his own words he refuses and continue to babble and smile. He will even start crawing like a baby. Does jealousy towards his baby brother have anything to with this language regression?

during the observation I noticed a sense of happiness after he starts to copy the baby and expects the same praise.