Now that the case has been made to encourage your child to learn both languages at the same time, what are some things we can do to help our kids learn them?
First, know what to expect! The following excerpt from an article gives us some insight:
“What should I expect when my child learns more than one language?
Every bilingual child is unique. Developing skills in two languages depends on the quality and amount of experience the child has using both languages. The following are some basic guidelines:
- Like other children, most bilingual children speak their first words by the time they are one year old (e.g., “mama” or “dada”). By age 2, most bilingual children can use two-word phrases (e.g., “my ball” or “no juice”). These are the same language developmental milestones seen in children who learn only one language.
- From time to time, children may mix grammar rules, or they might use words from both languages in the same sentence. This is a normal part of bilingual language development.
- When a second language is introduced, some children may not talk much for a while. This “silent period” can sometimes last several months. Again, this is normal and will go away.” 
Second, allow your children to be exposed to both languages. Let them do things in both languages. If they watch movies, let them watch it in both languages. If you read books to them, read in both languages.
“Research suggests that a child needs to be exposed to a language 30% of his or her waking time to actively speak it, and since waking time is a finite quantity, so, too, is language acquisition.” 
“Children learn to speak only when they hear people talk to them in many different circumstances. Language development in the early stages depends crucially on vocabulary knowledge. The more words children know, the better they will learn to speak and the better their chances of doing well in school. Book reading is an excellent source of help in the acquisition of vocabulary. Book reading in any language, even when a baby can hardly sit up yet, plays a highly supportive role not only in the learning of language but also in the emotional bonding between child and parent. Furthermore, it is an activity that is viewed in many cultures as appropriate for both mothers and fathers to engage in, and it is an excellent way of introducing children to aspects of culture that they may not see in their local environment.” 
“Do what comes naturally to you and your family in terms of which language(s) you use when, but make sure your children hear both (or all three or four) languages frequently and in a variety of circumstances. Create opportunities for your children to use all of the languages they hear. Read books to and with your children in each of the languages that are important to their lives.” 
Thirdly, come up with a practical plan, exercise patience and encourage your children along the way (depending on the child’s age and the language being learned).
“There are endless variations on the two most successful language systems. The most common involves one person who always speaks to the child in the ‘foreign’ language. Anyone who is spending a significant amount of time with the child can function as this primary speaker. The second most common language system is where the whole family speaks in the foreign language. To add another language beyond those already spoken within the family, or if your family doesn’t speak any foreign languages, you’ll need to provide an outside source like an immersion program, a nanny or an au pair.”
“…play dates that will provide your child with the ultimate language teachers – other kids. Books, music, movies, and toys in your minority language are the most obvious ways to boost your child’s exposure, but there is also an amazing range of other household items such as place mats, tableware, posters, etc.”
“As with most aspects of parenting, it’s a long term commitment and there will be ups and downs. But remember, that’s happening to the parents of the monolingual children too! Don’t worry if your child doesn’t speak his multiple languages as quickly or as adeptly as his peers. Instead focus upon his successes and marvel at the development of his little brain. Always praise, praise, and then praise some more!”
I hope these articles have helped you better understand how to raise a bilingual child like it has helped me. If you have an other ideas or helps, feel free to leave them in the comments.