How does the brain deal with two languages from birth? What are the advantages and disadvantages of bilingualism? And what does this mean for the children of Wales? This is the focus of the next Wynebau Newydd documentary.
One field that interests Enlli is the effect of bilingualism on children, and she has been working on a research programme in schools to find out whether there are any advantages for bilingual pupils.
The programme follows Enlli as she travels to York University in Toronto, Canada where the English and French languages live side-by-side, to meet Ellen Bialystock who has done pioneering work in the field.
However, it's not only children who can benefit from bilingualism. Another research project at Baycrest Hospital in Toronto shows how it can be helpful in our twilight years.
It appears that dementia in the elderly develops much slower in bilingual people, and that bilingualism can stave off the effects of dementia for up to four years.
Although this research is still in its infancy, Enlli is already looking forward to her next project.
"We're very lucky in Wales because we have two languages and a strong musical tradition. Something that interests me is what effects playing musical instruments can have on the brain. Maybe that will be my next research project."
© 2012 S4C
O Gymru / Made in Wales