Otto explains that borrowing occurs when the concept a person wants to use is not available in the second language. But this process is different depending on the stage at which the vocabulary is learned. Children who have acquired two languages ​​before the age of three will develop both vocabularies at the same time. On the other hand, in children older than three years, the acquisition of vocabulary for the second language will be reduced during the preschool years, especially because it is limited to practice at certain times of the day or week. It is worth noting that although code mixing and code switching may occur, children develop independence from one language to another faster than adults