A. prep. (in ordinary use, before a noun.)The Old English preposition tó normally ‘governed’ or was followed by the dative case, sometimes, idiomatically, by the genitive or the instrumental (esp. in tó þæs and to þý), rarely by the accusative. In later Middle and in modern English, to is followed by the ordinary ‘objective’ case, which in ns. is formally identical with the nominative, and in pronouns is the objective, me, him, etc. In Middle and modern English to not only represents the Old English preposition, but also takes the place of the Old English inflected dative case. Even in Old English the simple dative was often reinforced by tó, or (what came to the same thing) was supplanted by tó and its case. This was very frequent in late Old English, and (helped no doubt by the example of French, which had similarly substituted the construction with à (Latin ad) for the Latin dative) became universal in Middle English, the simple dative remaining only in pronouns and substantives as the indirect or remoter object, known by its position before the direct object (as in ‘give me the book’, ‘tell John the news’). Both with pronouns and nouns, the prepositional construction may, and in some cases must, be used (e.g. ‘give the book to me’, ‘tell it to John’). In Old English many verbs ‘governed’ or took a dative object; with the loss of the dative inflection, this case could no longer be distinguished from the accusative, and such verbs are now treated as ordinary transitive verbs governing the objective (e.g. sio heord folgað ðæm wordum & ðæm ðeawum ðæs hirdes, ‘the herd follows the words and the thews [customs] of the shepherd’).

The senses and uses of to may be arranged in various ways, every way having its peculiar difficulties owing to cross-currents of history and usage. Old English and the West Germanic Languages had two prepositions with the sense of modern to, viz. tó and óð; the second of these always expressed motion reaching its object; it is therefore probable that tó had originally the sense of ‘direction towards’, without any implication of reaching; and in a truly historical account of the word, it would perhaps be necessary to start with the two main divisions of ‘toward’ and ‘actually to’. But even in the earliest written Old English this distinction had, so far as concerns tó, faded away, and in the various transferred and later senses it could not be successfully carried out. Even the later distinction between to as a preposition implying motion, and to representing the dative inflection, can, from the falling together of these notions, only be partially exhibited. The arrangement here followed is thus largely tentative and practical, and not in every case historical.

B. to before an infinitive (or gerund: see A. 22).History:—Beside the simple infinitive, or verbal substantive in -an (Middle English -en, -e), Old English, like the other West Germanic languages, had a dative form of the same or a closely-related noun, which in Old English ended in -anne, -enne, in Middle English reduced successively to -ene, -en, -e, and was thus at length levelled with the simple infinitive, and with it reduced to the uninflected verb-stem. This dative form was always preceded or ‘governed’ by the preposition tó ‘to’. By many German writers it is called the ‘gerund’, after the Latin verbal noun in -ndum. In modern English the functions of the Latin gerund are more properly discharged by the verbal noun in -ing, and it is therefore more convenient to speak of the Old English form in -anne as the ‘dative infinitive’ or ‘infinitive with to’. Originally, to before the dative infinitive had the same meaning and use as before ordinary substantives, i.e. it expressed motion, direction, inclination, purpose, etc., toward the act or condition expressed by the infinitive; as in ‘he came to help (i.e. to the help of) his friends’, ‘he went to stay there’, ‘he prepared to depart (i.e. for departure)’, ‘it tends to melt’, ‘he proceeded to speak’, ‘looking to receive something’. But in process of time this obvious sense of the preposition became weakened and generalized, so that tó became at last the ordinary link expressing any prepositional relation in which an infinitive stands to a preceding verb, adjective, or substantive. Sometimes the relation was so vague as scarcely to differ from that between a transitive verb and its object. This was esp. so when the verb was construed both transitively and intransitively. There were several verbs in Old English in this position, such as onginnan to begin, ondrǽdan to dread, bebéodan to bid, order, bewerian to forbid, prevent, gelíefan to believe, þencean to think, etc.; these are found construed either with the simple (accusative) infinitive, or with tó and the dative infinitive. There was also a special idiomatic use (sense B. 13a) of the infinitive with tó as an indirect nominative, where logically the simple infinitive might be expected. From these beginnings, the use of the infinitive with to in place of the simple infinitive, helped by the phonetic decay and loss of the inflections and the need of some mark to distinguish the infinitive from other parts of the verb and from the cognate noun, increased rapidly during the late Old English and early Middle English period, with the result that in modern English the infinitive with to is the ordinary form, the simple infinitive surviving only in particular connections, where it is very intimately connected with the preceding verb (see below). To a certain extent, therefore, i.e. when the infinitive is the subject or direct object, to has lost all its meaning, and become a mere ‘sign’ or prefix of the infinitive. But after an intransitive verb, or the passive voice, to is still the preposition. In appearance, there is no difference between the infinitive in ‘he proceeds to speak’ and ‘he chooses to speak’; but in the latter to speak is the equivalent of speaking or speech, and in the former of to speaking or to speech. In form, to speak, is the descendant of Old English tó specanne; in sense, it is partly the representative of this and largely of Old English specan.(The simple infinitive, without to, remains: 1. after the auxiliaries of tense, mood, periphrasis, shall, will; may, can; do; and the quasi-auxiliaries, must, (and sometimes) need, dare: 2. after some verbs of causing, etc.; make, bid, let, have, in sense B. 15a; 3. after some verbs of perception, see, hear, feel, and some tenses of know, observe, notice, perceive, etc., in sense B. 15b; 4. after had liefer, rather, better, sooner, as lief, as soon, as good, as well, etc.: see have v. 47, rather adv. 8d, and the other words.)

The infinitive with to may be dependent on an adjective, a noun, or a verb, or it may stand independently. To an adjective it stands in adverbial relation: ready to fight = ready for fighting; to a noun it stands in adjectival or sometimes adverbial relation: a day to remember = a memorable day; to a verb it may stand in an adverbial or substantival relation: to proceed to work = to proceed to working; to like to work = to like working.