Although English is the most widely used language in the world, in America, England, Canada, Australia and New Zealand, where people speak English as a first language, learn second language or third language is also important. In addition to old standbys 
like Spanish, German and French, more and more students are opting for Eastern European and Asian languages, such as Chinese. Did you notice that Chinese students think it is very hard to learn English and American students think Chinese is the most difficult to learn. The learner of a second language has many obstacles to overcome. But why, if a child's parents come from different countries say different languages, the child is east to speak two kinds of languages? A child born their brain's weight is 350 g. One year old, 950 g; six years old, 1200 g, close to 1400 g adult's quality. One-year-old to six years, this period is the period of the fastest growing children's brain development, but also to accept the best period of the language. Specifically, you want the children are real but one language, you should start early, from the age of two, this period can allow children to accept the dual mother tongue language education. How to help parents to motivate their children to learn a second language? First, to see what to say. Second, use scenes of life to learn. Third, to learn language in the games. In a bilingual Environment, cross-language references makes the students' thinking more sophisticated.
Children Language Development
I agree with you that children who start learning two languages when they were children can understand and manage these two languages better than others. And according to our text book, it seems that the best period of time for learning languages is childhood. When people get elder, it becomes more and more difficult to manage different languages because not only the language learned before will get in the way of new language, but also the new language will mix the memory of the old one. Therefore, I guess it would be better it we choose to learn more languages at the yonger age.
I am totally agree about what you said in the blog. When I study English at the very young age, the english teacher always try to use many interesting things to attract our attention for the better understanding. Also when I was young, the language study will be much easier than the age become older. That is the reason why the chinese baby can speak very good english if they just grow up in the English speaking country. There is no difference between the hard level of the language, the only difference for us now will be the age.
In response to your blog, I would agree with you that if you wanted your child to be bilingual that playing games and matching pictures to words would be very helpful. But I believe that you left out an important detail that Professor Koeing talked about. For a child to pick up a second language and for it to be maintained the child most of the time needs infant directed social interaction. By doing so the parent or teacher's attention is only on the infant and it allows for close communication and reward for the child. In return making the child more likely to remember and participate in a second language.