We use Rosetta Stone for my kids. Its was a little pricey but I like the immersion method. My eight year old zips through it. Although he isn’t confident enough to try and speak it yet.
6 year old gets frustrated too quickly when he gets wrong answers. I try to reassure him that its ok to get it wrong. We can always go back and try again.
In the end, no matter what method you use, you simply have to go to a country or location where the language you’re trying to learn is the common tongue, and you are forced to use it exclusively, no English. It is going to take a few days of OMG-I-have-no-freaking-idea-what-is-going-on-here before your brain clicks over and gets it.
And if nothing else, here is one phrase you might want to learn: “Your English is (100) (1,000) (one million) times better than my (insert other language here.)” And you know what, for most of us, this is absolutely true. The guys who built our back yard fence were bilingual. We were obviously not. Who were the more educated people here? Certainly not us, in terms of multiple-language ability.
I have never encountered any rudeness or contempt by anyone at my attempts to speak their language, other than by the French, and that’s my most fluent language. Instead, I have found that most people are fascinated by foreigners, including Americans, and that they are cheerfully supportive of our floundering attempts to express ourselves. (Our most recent trip was to Cuba, and boy did we flounder, but they were cheerful and gracious.) The people that you are trying to talk to are much more kind and less judgmental than your French II teacher.
Maybe have your kids talk to someone at the local tienda, or the folks who clean your house or work on your yard. Again, I have never received anything but delight from Spanish-speakers who kindly see me flopping around like a fish on the bottom of a boat.
If you don’t mind being rescued by peeps from another culture, it’s an excellent way to integrate a new language.