Dyslexia refers to a language problem relating to the analysis of words in print. Identification of dyslexia often makes use of an exclusion criterion (e.g. IQ-achievement discrepancy) rather than several criteria. However, this exclusion criterion does not fit dyslexia properly as IQ tests in English are not reliable for a bilingual child whose language proficiency in English is still developing (e.g. immigrant children). The gap between indigenous and immigrant children decrease when immigrant children have been in the country for longer. This may lead children who are bilingual to not be identified as having a specific learning disorder (e.g. dyslexia).

IQ is likely to be underestimated in bilingual children while avoidance of IQ-tests will lead to under-identification. It may thus be useful to use a definition of dyslexia which does not make use of exclusionary criteria. Dyslexia is evident when fluent and accurate word reading and/or spelling develops very incompletely or with great difficulty. The problem is severe and persistent despite appropriate learning opportunities.

Differences in the orthography of a language influences the development of dyslexia. It is important to look at bilingualism in broad terms to properly detangle the effects of bilingual development on the development of dyslexia and vice versa. There are three dimensions to describe people’s associations with a language:

1. Expertise
   This refers to the degree of proficiency in a language.
2. Affiliation
   This refers to the affective relationship with a language.
3. Inheritance
   This refers to membership of a particular language tradition (e.g. by birth; by family)

Only looking at monolingual and bilingual children may use overinclusive categories and may neglect the emotional importance and developmental impact of affiliation and inheritance factors. Literacy practices in school may contradict expectations brought from other experiences for some children. Contextual factors in bilingualism may play an important role in the outcome of a child with dyslexia. When a parent helps a child in learning, the parent needs to adjust one’s help to the preferences of the child to have the best outcomes.

There are five major challenges for dyslexia and multilingualism:

1. Identification
   This refers to knowing where to look when one wants to identify dyslexia in bilingual children.
2. Defining dyslexia
   This refers to working with a clear, interactional model of the development of dyslexia.
3. Defining bilingualism
   This refers to taking into account dimensions of expertise, affiliation and inheritance.
4. Teaching strategies
   This refers to the strategies one can take to achieve the best balance between addressing the children’s needs as second language learners and addressing the specific needs that relate to dyslexia.
5. Involving families
   This refers to finding effective strategies for supporting families to play an active part in the children’s progress towards literacy.