I was raised bilingual and am raising my 5 kids bilingual. It's funny, but I'm doing the exact opposite of what my parents did - I'm raising English-speaking children in Israel, when my parents raise Hebrew-speaking children in the US.

My parents are both Americans & they raised me and my 4 siblings speaking Hebrew. They insisted we speak in Hebrew both to them and to each other. I found there to be two problems, the first being that my 3rd brother had difficulties with Hebrew as he grew older and had trouble expressing himself. They refused to "give in" and he felt he couldn't express himself as he would have wanted to, which really frustrated him and made him less interested in talking to my parents. The second issue was that in forcing us to speak Hebrew to each other, they made us basically lie to them, since English was much easier for us and we spoke in English whenever we could...

My husband is Israeli, but he speaks English very well. We both speak to our daughters in English, but he says that at some point he will switch over to Hebrew (which makes sense). With my oldest daughter, my ex & I both spoke to her in English and her English is great (she really sounds like an American even though her only visit to the US was for a month when she was 5-months-old). With my twins (turning 10 on June 6), I was so tired that I didn't speak to them enough in general. My ex was not around, so I didn't have support in that sense either. Today they both speak English fairly well, but my daughter has difficulty with the language, so whenever she has trouble understanding, I explain to her in Hebrew too.

For all the kids, I used English videos and books as well, to reinforce the English in any way possible. I didn't keep them away from Hebrew - just let them grow up in the natural environment (kids speak Hebrew in the park, in nursery school, etc.)

I know a lot of people who teach their children two languages simultaneously (each parent uses a different language) - it's a little too confusing for me (I can picture situations where we're both trying to say something to the child and each using a different language), but I know it works well. I think the key is to be consistent - if you have decided to speak to the child in one language, to *always* speak to them in that language. One of the things you hear a lot in Israel is English-speaking kids who speak sentences that are all mixed up...

We have two kids and they can speak and understand both English and Danish.  What I think is important is that each parent talks to their children in their mother tongue some of the time.  My wife speaks Danish to the kids and I speak mainly English.  Though I speak Danish with my wife.  They go to school in English and the moment, but in a year, they will be in a Danish environment.  Being a psychologist and linguist I know the studies that show what a significant benefit billingual children have over children with only one language in a number of skills, particularly creativity, emotional intelligence, lateral thinking.  It is also great for a granddad or grandmum to be able to speak to and be understood by their grandkids.  Make the effort, it is certainly worth it.  Remember too that if your child cannot understand your mother tongue, they may never have the understanding of who you are and where they come from.  It's a great gift. Give it to them.

I had an interesting conversation with a French guy who was living in England with his English wife. I was asking him if he was going to bring up his daughter to speak French, and he tells me she does understand (she was around 1) both French and English, but that she was always going to pick up language quicker from his wife - he reminded me of the phrase "mother tongue" and I could see where he was going with that.

I have a friend who is Spanish and lives here in England with her English husband. Their 2 yr old speaks both languages as much as a two year old can, but will often pick whichever language has the easier word - 'ball' and 'toys' in english, but 'aqua' for water. Her Mum talks to her in Spanish most of the time, and she learns English at nursery and from her Dad.

I also have a turkish brother-in-law with an English wife. Their daughter, now 12, can speak some turkish but is very shy doing so, and tends to save it for when she goes to visit her cousins in Turkey every summer. Although her Dad speaks Turkish to her, for about 3 or 4 she has refused to answer him.

I understand that children who are learning two languages from birth do tend to be a bit slower speaking and putting words together, but the opportunity to learn perfect pitch and tones from languages goes quite quickly as a child learns to ignore those not relevant to their language. Once they get past the initial hurdles, they have the most amazing gift - I wish I could get my children fluent in two languages, and keep meaning to get them to a Spanish group. Good luck, and I hope it works well.

My sister's husband is Romanian.  They have two children.  My sister knows a few romanian words and uses those with her children.  Her husband speaks a little more romanian to them.  He teaches them the words the same way we do with english.  Consistency and demonstration. They have operated like this since the children were born.  It is amazing how the eldest, 8 years old, can differentiate between the two.  I think the key is to expose them to the non-english language as much as possible, just the way we teach them english.  I have friends who do it differently.  They speak spanish at home and the kids learn english outside the home.  they are well spoken children. check this site http://www.multilingualchildren.org/getting_started/tensteps.html