If you are here, you are likely a bilingual or multilingual parent who wants to teach a second language to your child.
As it is with learning anything new, language development takes time. So the earlier you start, the better.
Raising bilingual children may feel like a challenge, without knowing where to begin. Especially if your child has already started talking, but toddlers are still learning new words, their pronunciation, and how to make phrases in one language. There's so much more that they can learn and this is the ideal age to learn a new language.
Start as soon as possible, there's no better time than right now!
2 to 3-year-olds are currently building their vocabulary, so this is a great time to expose your child to multiple languages. Linguistics suggests that the ability to hear certain phonetic pronunciations of words is at its peak and fades over time if they aren't repeated. So introducing your child to music and television in the said, secondary language would be ideal. It's approaching both the native language and the secondary language at the same time, which makes your child appreciate both and they will likely have paralleled language acquisition approach for both. Leave it up to them to decide what their dominant language will be.
You can also read books, watch television shows together and contextually understand what is being said. You can use visuals to your advantage, where it's easier for the child to comprehend what is what.
Foster a casual learning environment
A second language for toddlers should come naturally to them. Toddlers' brains are like a brook or a river, often following the paths of least resistance. Their bilingual language development would greatly depend on how it's introduced to them.
Make language learning a part of their daily routine by either spending a certain set of hours per day, comparing words from one language to another. Name everyday objects in both their first and second language. Children naturally gravitate towards the language that their parents speak, bilingual parents can have their toddlers partake in a conversation with them. Correct them as they go, not obsessively, but rather in an educative manner.
Teach one word at a time
Use the approach of talking twice. Whenever you use a noun to point something out in one language, and then immediately tell them what it's called in the other language. This helps them understand that the same thing can have different names in different languages. If you have a predominantly English-speaking household, you can first name something in English, followed by the heritage language.
Find relatives who speak the second language
The more the merrier! Relatives and immediate family members, who speak the same second language as you and your child, can be a great learning ground for your bilingual child. When they hear the same language that you repeat to them every day, and they see you conversing with relatives and repeating the same words, it makes them believe that this language is also a medium for understanding. It's not that technical, but simply using the same salutations and nouns for objects is enough.
Set realistic expectations
When you are introducing your toddler or monolingual children, you are not conditioning them to be absolutely fluent without fault. Just like English requires lessons in a curriculum, your child would likely need formal education in the minority language as well. They will have a good grasp of the phrases and may develop fluency to a certain level, but you would need them to undergo a formal language development lesson or class to truly master it. This is especially true if you live where the minority language isn't spoken.
Expect them to make mistakes or use more than one language at once. This mix-up would often disappear when they grow up, or they would learn how to articulate sentences based on the environment.
Have some fun
Last but not least, have some fun in this process of learning a language. Learning a new language doesn't need to be all about language development, vocabulary building, or pronunciation. It's called bilingual parenting, with parenting being a crucial part of it. Let your child just be a child and slowly strengthen their grasp on their new form of expression.
Just stay mindful consistent and forgiving, and everything will work out at its natural pace.