It seems fairly obvious that understanding - implicitly or explicitly - how grammar works requires concept development. Vocabulary development also requires concept development as we map out the meanings of new items of vocabulary, eg between pendule and horloge in French, both expressed by clock in English. And it also helps if we have clear conceptual representations of the key tasks we need to perform, particularly those which are complex, such as writing an academic essay.

All of these are areas which language teachers may need to address explicitly. While some learners are able to develop a wide range of second language concepts through implicit induction, other learners are not and therefore need our help. Furthermore, making existing implicit concepts explicit seems to help in the development and extension of those concepts. While implicitly induced concepts can be used quickly and easily in the performance of a skill (in this, they constitute procedural knowledge), they may be limited in their scope. If they remain implicit, they may 'fossilize', such that we cease to be able to restructure them to take account of 'new' phenomena.

An example of this is highlighted by Broady and L'Huillier (2002) They found that advanced students of French often relied on implicit induction in selecting the correct article for a translation task. In particular, students seemed to associate use of the partitive article (du, de la, des) with food and drink nouns in object position. This is a reasonable induction, since the partitive article is usually used with the objects of verbs of eating and drinking (J'ai mangé du poulet - I ate some chicken; J'ai bu du vin - I drank some wine). However, this induction also led them to use the partitive article with food and drink objects of liking/disliking verbs (eg J'aime du* café - I like coffee). Since these verbs imply generic reference, the definite article (J'aime le café) is required in French. Students who were able to check their implicit induction against explicit deduction, by referring explicitly to known rules of French grammar, were able to correct their erroneous productions.

This raises issues about the relative value of implicit and explicit learning in second language development. Reflective task 13 sheds further light on this.

Reflective task 13