“…the ideas of science are often difficult. But learning to use the language of science is fundamental to learning science. As Vygotsky (1962) pointed out, when a child uses words he or she is helped to develop concepts. Language development and conceptual development are inextricably linked. Thought requires language, language requires thought. Viewed from a negative angle, ‘difficulty with language causes difficulty with reasoning’ (Byrne et al. 1994).” (p.6)
Ref: (italics in original, emphases in blue bold, mine) Jerry Wellington and Jonathan Osborne (2001) Language and Literacy in Science Education. Open University Press: Buckingham, Philadelphia.