I’ve just finished writing an article on maintaining Mother Tongue (for a new publication called The Underground, out in The Hague in November) and it started me thinking about the sometimes sticky topic of Mother Tongue. This is a subject that comes up often in the question period of my seminars. Historically, of course, Mother Tongue was the language spoken by the mother, and was likely to be the child’s strongest language. In the world of language research now, this term has been replaced with the more objective L1 (Language 1) and L2 (and L3, and so on…). So, what constitutes an L1? For those of us who were raised as monolinguals, L1 is the language we have heard since birth. For those who were raised as bilinguals, the term L1 actually applies to *both* of the languages heard from birth (or, arguably, from very young). For these lucky people, L2 designates any language learned later in life. It seems counter-intuitive to refer to two languages as “L1”, but in fact, this is a dual-L1, and in old-speak we would say that these people have a double Mother-Tongue. This is an important point to remember for discussions on maintenance and promotion of L1, which I will come to in later posts.