During my holidays in Spain in met a family made up of two grandparents, their daughter, her husband and their two children from 3 to 7 years.
Grandmother was French and grandfather was Spaniard and both lived in Spain; their daughter was married to a Frenchman, son of an Englishman and a Frenchwoman, who lived in France with their two sons. They were also with an English friend.
I was surprised by the way adults spoke to children, alternately in English, French or Spanish and how children answered them spontaneously in the language they had been talked to.
I mean, if they were asked in English, they replied in English, and it happened the same with French and Spanish.
I thought those children had a gift for languages, but days after I realized that children didn’t speak three languages, English, French and Spanish, they only spoke ONE LANGUAGE, which a vocabulary made up of English, French and Spanish’s words and synonymous .
Children had achieved in a completely intuitive way THE FUSION OF THREE LANGUAGES IN ONE. Of course, with three times of vocabulary.