Werner Abraham & Elisabeth Leiss 
Covert Patterns of Modality [PDF ebook] 

This typological overview compares the degree to which different languages have means to give expression to modality (possibility, necessity) without lexical and direct inflectional means. The criterial patterns derive from a variety of languages such as German, English, Chinese, French, Scandinavian, Italian, Romanian, Russian, Polish, and Gothic as well as Old High German. They encompass mainly the auxiliaries HAVE and BE, together with either an infinitival embedding of a full verb linked by the infinitival preposition TO, or other aspectual means. It is demonstrated that what appears as typical covert modal expressions in the Germanic languages, and the Indo-European ones in a wider sense, cannot be seen as a recurrent pattern in non-Indo-European languages. Yet, there are recurrent and plausible forms that allow for generalizations.