Preterite-present verbs

The preterite-present verbs are a class of verbs which have a present tense in the form of a strong preterite and a past tense like the past of a weak verb. These verbs derive from the subjunctive or optative use of preterite forms to refer to present or future time. For example, witan, "to know" comes from a verb which originally meant "to have seen" (cf. OE wise "manner, mode, appearance"; Latin videre "to see" from the same root). The present singular is formed from the original singular preterite stem and the present plural from the original plural preterite stem. As a result of this history, the first-person singular and third-person singular are the same in the present.

Few preterite present appear in the Old English corpus, and some are not attested in all forms.

Note that the Old English meanings of many of the verbs are significantly different than that of the modern descendants; in fact, the verbs "can, may, must" appear to have chain shifted in meaning.

Preterite-Present Verbs occupy a specific place within the verbal system of OE verbs. They combine the qualities of the strong verbs as well as weak verbs. Their present tense is formed according to the rules of formation of the past tense of strong verbs that is by gradation (vowel interchange) their past tense has all the peculiarities of the weak verbs. It is just that peculiarity that makes them preterite (форма прошедшего времени) (in form) and present (in the meaning). In general, past tense has a strong tinge (оттенок)result in its meaning. A certain group of verbs preserves this strong meaning of result and it turns into their dominant feature, they begin to render the present result of the past action. So the past tense in structure like Ic cann swimman meant and was perceived as the present state of mind of the speaker. However there were situations in which the past tense was still required: one might want to know that once there was a man who could swim. So there appeared the form : he cuðe swimman. Participle II had the necessary meaning of result and some verbs preserved it, formed by gradation and the suffix –en, while with some other the pattern of weak verbs was used. The verbs of this group with overburdened system of forms, started losing certain parts of their paradigm. Most preterite-present verbs are classified according to the classes of gradation to which their present tense belongs.

Conjugation	Pronoun	'know, know how to'	'be able to, can'	'be obliged to, must'	'know'	'own'	'avail'	'dare'	'remember'	'need'	'be allowed to, may'
Modern Descendant		'can'	'may'	'shall'	'wit (obsolescent)'	'owe'	'dow (archaic)'	'dare'	--	--	'mote (archaic), must'
Infinitives		cunnan	magan	sculan	witan	āgan	dugan	durran	munan		mōtan
Present Indicative
	ic	cann	mæg	sceal	wāt	āh	deah	dearr	man	þearf	mōt
	þū	canst	meaht	scealt	wāst	āhst		dearst	manst	þearft	mōst
	hē/hit/hēo	cann	mæg	sceal	wāt	āh	deah	dearr	man	þearf	mōt
	wē/gē/hīe	cunnon	magon	sculon	witon	āgon	dugon	durron	munon	þurfon	mōton
Past Indicative
	ic	cūðe	meahte	sceolde	wisse, wiste	āhte	dohte	dorst	munde	þorfte	mōste
	þū	cūðest	meahtest	sceoldest	wissest, wistest	āhte	dohte	dorst	munde	þorfte	mōste
	hē/hit/hēo	cūðe	meahte	sceolde	wisse, wiste	āhte	dohte	dorst	munde	þorfte	mōste
	wē/gē/hīe	cūðon	meahton	sceoldon	wisson, wiston
Present Subjunctive
	ic/þū/hē/hit/hēo	cunne	mæge	scule	wite	āge	dyge, duge	durre	myne, mune	þyrfe, þurfe	mōte
	wē/gē/hīe	cunnen	mægen	sculen	witaþ
Past Subjunctive
	ic/þū/hē/hit/hēo	cūðe	meahte	sceolde	wisse, wiste
	wē/gē/hīe	cūðen	meahten	sceolden