Bilingualism, a term used to describe mastering two languages, does not cause confusion.
Children are able to learn two languages at the same pace as other children who are learning only one language. In fact, early childhood is the best possible time to learn a language. Children who experience two languages from birth typically become native speakers of both. Teaching young children how to speak a second language is good for their minds because they are able to think a little more flexibly because they can switch between one language and the other. Of course, you can always learn a second language later, but it takes more time and becomes more challenging.
It can be normal for children learning more than one language to experience interference, when the grammar and structure of one language influences the grammar of the other language they are learning, which leads to grammatical errors. This is not a language disorder, but a normal part of learning two languages. Children may also go through a silent period when acquiring a second language, which happens as they focus on listening to and comprehending the new language. This can last anywhere from a few weeks to a year, depending on the age of the child. These things sort themselves out. It can take five to seven years for a child to master academic language, even if they are proficient users of the second language in social situations and conversation.
Research shows that learning a second language boosts problem solving, critical thinking, and listening skills, in addition to improving memory,concentration, and the ability to multitask. Children proficient in other languages also show signs of enhanced creativity and mental flexibility. The experience of learning a language introduces them to the world in ways they might otherwise have not experienced because of the cultures associated with those languages.