I don't have experience in moving the children back from French to English school, but our children have been to French school too from 2 ½ years old and once they could read and write in French, they automatically could do the same in English and German (as I'm German). We never taught them to read - they learnt the French at school and all of a sudden read English whenever there was something to read. I don't know how this happens in their brain, but apparently it's absolutely normal. The only thing that doesn't come AS easy is the German spelling, as they did it phonetically the way they pronounce it in French, but once I correct them, that's done. My son is now 14 and at lycée and for the first time "learns" German and is doing absolutely great. In the first test he made a few mistakes as he didn't write all nouns with capitals - but now he knows, it seems easy peasy.
So really I wouldn't worry - children learn and soak up so easily!
You do not say whether the twins are male, female or mixed. If male they may take longer to adjust though at least they already understand English. I would not be in any hurry to put them into primary school before the age of about 5. They need to play. Making friends is the most important aspect of school life if a child is to excel.....but I guess twins already have one friend!
As for the school itself make sure there is no doubt you are in the catchment area for the state primary school you want for them. Unless it is a private school your children will stop using any french as soon as they return to the UK (probably) so they will not get confused and should easily adjust.
Hi Jemima
There would be no problem in moving back to the UK while the children are in primary school. I used to work at the European School nr Oxford. Children start school age 6, and immediately start learning a 2nd language. However they do not start to read/write it in the first term or 2 to give them time to get to grips with doing it in their own language.
I would say though, that once you are back in the UK, the children will probably see no use or benefit of keeping up with French, so maintaining any fluency in an English environment will be very difficult, if not almost impossible My children went to the European School (English section) and although they learned French to a very high level, they could see no point as their friends were English, and the children in the French section spoke English too. They were so reluctant that even when we went on holidays to France they wouldn't go and buy an ice cream! So - if you want the twins to be bilingual, probably better to stay in France! (Though of course maybe a return to the UK is essential for you).
Hi Jemima
No, it will not "set them back". What you have heard is an old school of thought. Children are naturally smart ! My daughter learnt French ( from me + my constant struggle to keep the "balance" - see further on ) and English ( Dad + her English environment). Then we moved to France when she was 5 1/2. She could integrate no problem. She is now 17 and FULLY bilingual / bicultural. Isn't it what you'd like for your twins ?
The "secret" is to manage a good balance between the 2 (or more !) languages AND cultures ( the 2 notions just cannot be without each other ). Also one vital rule is to always speak your native language to the child. In case of a "mixed" couple it's a matter of " one parent <-> one language ". If you go back to the uk and want the children to carry on speaking French, a French au-pair ( with a CAP Petite Enfance, preferably ) is a good option + French TV - definitely ! ;)
However I know of true bilingual twin kids, same age as my daughter. Twins are known to have some "language delay" because of the way they communicate with one another. So it's NOT about the second language, it's because it's a "twin thing". Then they catch up, anyway.
Please don't give up on either languages. It would be a great shame.
Any piece of advice, feel free to ask : I've been there. Got the T-shirt !!!
Many FB pages / groups about the subject :
https://www.facebook.com/bilingualbicultural
https://www.facebook.com/UKbilingualtoddlers
https://www.facebook.com/BilingMatters
https://www.facebook.com/TrilingualChildren
https://www.facebook.com/Multilingual.Families
AND SO ON !
https://www.facebook.com/multilingual.parenting
I did do a search on facebook but couldn't find anything. Do you know the names of any of the groups?