Epistemic usages of modals tend to develop from deontic usages. For the meanings of such constructions with the various modals, see English modal verbs. However, epistemic modals do not necessarily require inference, reasoning, or evidence. In English, modals form a very distinctive class of verbs. The preterite forms of modals are used in counterfactual conditional sentences, in the apodosis ("then"-clause). Some verbs ceased to function as modals during the Early Modern period. Epistemic modals are used to indicate the possibility or necessity of some piece of knowledge. Double modals also occur in the closely related Germanic language Scots. Multiple modals combine these two modalities. Just like English, Danish depends on tense and modals to express moods. Mpi (Loloish) contrasts modals and stiff voice in its vowels. A greater variety of double modals appears in some regional dialects. In some Southern regions, multiple modals are quite widespread and not particularly stigmatized. For details of the uses of the particular modals, see below. Another publication "Modality and the English Modals" had already appeared in 1979.