Might is always considered a modal in English. However, and that is why I think yours is a good question, in other languages, such as my own – which is Dutch – we do in fact add an adverb to the verb phrase of the sentence. In the end, the

What books would you recommend to learn more about the modal verbs? I've written here, on alt.english.usage and on uk.culture.language.english; ... I would need some reliable reference based on grammar (correct usage), and actual current usage