Growing up as bilingual myself, languages and how we learn them has always interested me. As a Speech and Language Therapist I get asked questions by parents on a daily basis about how to support their bilingual children.
1. Will learning 2/3/4/5 languages confuse my child?
Some bilingual children may mix grammar rules from time to time, or they might use words from both languages in the same sentence (e.g. "Voglio water" [I want water]). This is a normal part of bilingual language development and does not mean that your child is confused. It is also a normal part of any bilingual individual's communication style, this is known as "code mixing" and it happens when an individual speaks to another individual who speaks their same languages and they may start speaking in one language and add in vocabulary or grammar from their other language which may suit the topic of conversation better - this doesn't mean that they are confused!
2. My child isn't talking yet and is 2, is it because they are bilingual?
Developmental milestones for children who speak one language and the same as for children who speak more than one language. That is; at one children start using single words and at two they start joining words together. Bilingualism should never be used as an excuse for language delay or disorder.
3. I speak XYX language but my doctor told me that I should only speak to my child in English, what should I do?
This question often comes to me from families where English is not the most dominant language but my advice is always the same. Speak to your child in the language that you are most proficient in. You don't want to be teaching your child the wrong grammar and vocabulary in a language that you are not confident in. If your child develops their first language proficiently, this will serve as a strong foundation for learning other languages. So if your main language is Italian, Spanish, Cantonese, Gujarati etc speak to your child in that language, they will learn English at school, and without too much fuss as they can draw from knowledge of how their first language works.
If you are lucky enough to have more than one proficient language then use all of them and re-read question number 1!
4. Will my bilingual child have academic difficulties at school?
Again: Bilingualism should never be used as an excuse for language delay or disorder. Or even intellect.
Research tells us that there are many benefits to being bilingual such as increased problem solving, ability to concentrate, a delayed onset of dementia, increased job opportunities... The list goes on and on. Therefore children who speak more than one language are actually expected to do better at school than their monolingual peers. However if your bilingual child is having difficulty at school, the reason for this does not lie with them being bilingual and it could be due to a number of confounding variables which are never easy to pick apart.
5. Where can I go for more information?
I like the following sources of information, and there are also a couple of fun and interesting articles listed.
François Grosjean (French Psycholinguist and Bilingualism Guru) https://www.francoisgrosjean.ch/index.html
Article by Tobias Jones about the Joys and Benefits of Bilingualism and the impact it had on his own family. https://www.theguardian.com/commentisfree/2018/jan/21/the-joys-and-benefits-of-bilingualism
Article by Gaia Vince on the Amazing Benefits of Being Bilingual. http://www.bbc.com/future/story/20160811-the-amazing-benefits-of-being-bilingual
The London Bilingualism Special Interest Group has lots of information and resources. http://www.londonsigbilingualism.co.uk/