Class I Verbs

Class I verbs actually consist of three classes in Proto-Germanic:

Class II Verbs

Class II verbs were formed with a suffix -ō-. In the northern West Germanic languages, an alternative extended suffix -ōja- sometimes appears in the non-past forms, e.g., the Old English infinitive -ian < *-ōjan.

The following is a cross-language paradigm of **laþōną "to invite" (Gothic laþōn, Old Norse laða, Old High German ladōn, lathōn, Old Saxon lathian [-ōjan], ladian [-ōjan], Old English laþian, Old Frisian lathia).

Class III Verbs

What is known as "Class III" was actually two separate classes in Proto-Germanic:

• A class of verbs with stative semantics (i.e., denoting a state rather than an action), formed with a present suffix that was either *-ai- or *-ja-, and no suffix in the past.
• A class of verbs with factitive semantics (i.e., with the meaning "make X" where X is an adjective or noun, e.g., "renew, enslave"), formed with a suffix that was either *-ai- or *-ā-, and a suffix *-a- in the past.

The histories of this class in the various Germanic languages are quite varied:

• Old High German combined both into a single class and generalized *-ai- (appearing as -ē- through regular sound change) to all forms of the present and past.
• Gothic combined both into a single class, keeping the *-ai-/-ā- alternation of the factitives in the present, generalizing the alternation to the statives as well, and borrowing *-ai- as the past suffix.
• Old Norse for the most part combined both into a single class in the same fashion as Gothic; however, two relic stative verbs (segja "to say" and þegja "to be silent") preserve the stative suffixes in both present and past, and a third verb (hafa "to have") is a mixture of the two, with factitive suffixes in the present indicative plural and imperative and stative suffixes in the present indicative singular and past participle (elsewhere, the two types have fallen together).
• The other (i.e., northern) West Germanic languages have only small numbers of Class III verbs—but they consistently follow the stative paradigm, unlike the three languages above.

An example is the stative verb reconstructed as Proto-Germanic **habjaną "to have", past indicative third-person singular *habdē:

• Old English hebban < *habjan, past, third-person singular hæfde — derived entirely through regular sound changes.
• Old High German habēn, past, third person singular habēta — derived through analogical spread of suffix -ē-.
• Gothic haban, past, third-person singular habáida — derived through various analogical changes.
• Old Norse hafa, past, third-person hafði — partly regular, partly analogical.

Only four stative verbs survive as Class III verbs in the northern West Germanic languages (i.e., Old English, Old Saxon, Old Frisian and Old Low Franconian):

• **sagjaną "to say"
• **libjaną "to live"
• **habjaną "to hold, have"
• **hugjaną "to think"

However, there are five more verbs that appear as Class III verbs in Old High German, Gothic, and/or Old Norse that also have remnants of the stative conjugation in one or more northern West Germanic languages:

• **þagjaną "to be silent"
• **siljaną "to be silent"
• **þuljaną "to endure" (normally Class II þolian in Old English, but compare archaic umlauted infinitive -þoelġe; Class III in Old Norse þola)
• **fijaną "to hate"
• **hatjaną "to hate" (normally Class II hatian in Old English, but compare umlauted nominalized present participle hettend "enemy"; Class III in Gothic hatan)

Class IV Verbs

Class IV verbs were formed with a suffix -nan, e.g., Gothic fullnan "to become full". The present tense was conjugated as a strong verb, for example, Gothic fullna, fullnis, fullniþ, etc. The past tense was conjugated with suffix -nō-, e.g., Gothic fullnōda, fullnōdēs, etc. This class vanished in other Germanic languages; however, a significant number of cognate verbs appear as Class II verbs in Old Norse and as Class III verbs in Old High German. This class has fientive semantics, that is, "become X," where X is an adjective or a past participle of a verb.

• Examples of deadjectival Class IV verbs in Gothic are ga-blindnan "to become blind" (blinds "blind"), ga-háilnan "to become whole" (háils "whole").
• Examples of deverbal Class IV verbs in Gothic are fra-lusnan "to perish" (fra-liusan "to destroy"), ga-þaúrsnan "to dry up, wither away" (ga-þaírsan "to wither"), mikilnan "to be magnified" (mikiljan "to magnify"), us-háuhnan "to be exalted" (us-háuhjan "to exalt").

Note that the last two are deverbal even though the underlying root is adjectival because they are formed to other verbs (which are in turn formed from adjectives).

The vast majority of Class IV verbs appear to be deverbal. Class IV verbs derived from weak verbs keep the same stem form as the underlying weak verb. However, class IV verbs derived from strong verbs adopt the ablaut of the past participle, for example:

• dis-skritnan "to be torn to pieces" (Class I dis-skreitan "to tear to pieces")
• us-gutnan "to be poured out" (Class II giutan "to pour")
• and-bundnan "to become unbound" (Class III and-bindan "to unbind")
• dis-taúrnan "to be torn asunder, burst asunder" (Class IV dis-taíran "to tear asunder, burst")
• ufar-hafnan "to be exalted" (Class VI ufar-hafjan "to exalt")
• bi-auknan "to abound, become larger" (Class VII bi-aukan "to increase, add to").

Modern paradigms

One of the regular weak verb conjugations is as follows.

Strong to weak transformations

As an example of the rather common process of originally strong verbs becoming weak, we may consider the development from the Old English strong verb scūfan to modern English shove:

• scūfan scēaf scofen (strong class 2)
• shove shoved shoved

Many hundreds of weak verbs in contemporary English go back to Old English strong verbs.

In some cases, a verb has become weak in the preterite but not in the participle and may be thought of as "semi-strong" (not a technical term). Dutch has a number of examples:

• wassen waste gewassen ("to wash")
• lachen lachte gelachen ("to laugh")

An example in English is:

• sow sowed sown (strong class 7 with weak preterite)

Often, the old strong participle may survive as an adjective long after it has been replaced with a weak form in verbal constructions. The English adjective molten is an old strong participle of melt, which is now a purely weak verb with the participle melted. The participle gebacken of the German verb backen (to bake), is gradually being replaced by gebackt, but the adjective is always gebacken (baked).

Weak to strong transformations

The reverse process is very rare and can also be partial, producing "semi-strong" verbs as in show showed shown (originally a weak verb with its participle modelled on sown)

Weak verbs that develop strong forms are often unstable. A typical example is German fragen (to ask), which is historically weak and is still weak in standard German. However, for a time in the 18th century, the forms fragen, frug, gefragen by analogy with, for example, tragen (to carry) were also considered acceptable in the standard. They survive today (along with a present tense frägt) in the Rhinelandic regiolect and underlying dialects. In Dutch, the new strong past vroeg of the cognate vragen is standard today, but its past participle is weak gevraagd (though some dialects do have gevrogen).

Denominative derivation

The vast majority of weak verbs are secondary, or derived. The two main types of derived verbs were denominative and deverbative. A denominative verb is one that has been created out of a noun. The denominative in Indo-European and early Germanic was formed by adding an ablauting thematic *-yé⁄ó- suffix to a noun or adjective. This created verbs such as Gothic namnjan 'to name'.

Causative verbs

A significant subclass of Class I weak verbs are (deverbal) causative verbs. They are formed in a way that reflects a direct inheritance from the PIE causative class of verbs. PIE causatives were formed by adding an accented affix -éy- to the o-grade of a non-derived verb. In Proto-Germanic, causatives are formed by adding a suffix -j/ij- (the reflex of PIE -éy-) to the past-tense ablaut (mostly with the reflex of PIE o-grade) of a strong verb (the reflex of PIE non-derived verbs), with Verner's Law voicing applied (the reflex of the PIE accent on the -éy- suffix):

• *bītaną (I) "to bite" → *baitijaną "to bridle, yoke, restrain," i.e., "to make bite down"
• *rīsaną (I) "to rise" → *raizijaną "to raise," i.e., "to cause to rise"
• *beuganą (II) "to bend" → *baugijaną "to bend (transitive)"
• *brinnaną (III) "to burn" → *brannijaną "to burn (transitive)"
• *frawerþaną (III) "to perish" → *frawardijaną "to destroy," i.e., "to cause to perish"
• *nesaną (V) "to survive" → *nazjaną "to save," i.e., "to cause to survive"
• *ligjaną (V) "to lie down" → *lagjaną "to lay," i.e., "to cause to lie down"
• *sitjaną (V) "to sit" → *satjaną "to set, seat," i.e., "to cause to sit"
• *faraną (VI) "to travel, go" → *fōrijaną "to lead, bring," i.e., "to cause to go"
• *faraną (VI) "to travel, go" → *farjaną "to carry across," i.e., "to cause to travel" (an archaic instance of the o-grade ablaut used despite the differing past-tense ablaut)
• *grētaną (VII) "to weep" → *grōtijaną "to cause to weep"
• *lais (I, preterite-present) "(s)he knows" → *laizijaną "to teach," i.e., "to cause to know"

Essentially, all verbs formed this way were conjugated as Class I weak verbs.

That method of forming causative verbs is no longer productive in the modern Germanic languages, but many relics remain. For example:

• The original strong verb fall fell fallen has a related weak verb fell felled felled, which means "to cause (a tree) to fall"
• Strong sit sat sat and lie lay lain are matched with weak set set set and lay laid laid, meaning "to cause something to sit" or "lie" respectively.

In some cases, phonological or semantic developments make the pairs difficult to recognise. For example:

• Rear is the regular phonological development of Proto-Germanic *raizijaną given in the above list, but the connection between rise and rear is no longer obvious. (One might guess that the counterpart of rise would be raise, but raise is a borrowing from Old Norse, *raizijaną continues regularly.)
• Drench was originally the causative of drink, but the modern meaning of "drench" ("to cause to get wet") is no longer similar to "cause to drink".
• Similarly, German strong leiden litt gelitten ("to suffer") has the derived weak verb leiten ("to lead"), which makes sense when one realises that leiden originally meant "walk, go" and came to its present meaning through the idea of "undergoing" suffering.

Other types

There are primary verbs that date to Indo-European that took a weak conjugation because they were unable to take a perfect, including verbs that had zero grade of the root in the present and so were unable to show the ablaut distinction necessary for a strong preterite. That was the case with the Gothic verbs waurkjan "to work, create," bugjan "to buy," and sokjan "to seek."

Preterite-present verbs are primary verbs in which the PIE present was lost, and the perfect was given a present meaning. They needed a new past tense, which followed the weak pattern.

Most borrowings from other languages into Germanic were weak. However, this was not always the case: for example, *skrībaną 'to write' from Latin scrībō.

Origin of dental suffix

The origin of the dental suffix is uncertain. Perhaps the most commonly held theory is that it evolved out of a periphrastic construction with the verb to do: Germanic **lubō-dē- ("love-did") > *lubōdē- > Old English lufode > loved or **salbō-dē- ("salve-did", i.e., "put salve") > **salbōdē- > Old English sealfode > salved. That would be analogous to the way that in modern English one can form an emphatic past tense with "did": I did love, I did salve.

The common PIE root *dʰeh₁- meaning 'do' was a root aorist and so did not take a perfect. However, it took a reduplicating present. The imperfect of the root is probably the origin of the dental suffix.

That view is not without objections:

• Germanic has long -ē- in the plural, which cannot directly reflect the Proto-Indo-European situation.
• Reduplication is only in the Gothic plural, not in the singular.

The objections are sometimes answered as follows:

• There might have been a refashioning according to cases like *gēbun, namely, *gegbun > gēbun: *dedun → dēdun.
• Reduplication only in the plural can easily be explained by haplology in Proto-Germanic (*dede- being reduced to *de-) for the singular, with a later development of haplology for the plural in non-East Germanic languages.

Another theory is that it came from a past participle ending, a final *-daz from PIE *-tos (compare Latin amatus), with personal endings added to it at a later stage. That theory, however, is also disputed because of its inability to explain all the facts.

According to Hill (2010), the endings, which in the singular do not show reduplication in any Germanic language, continue the PIE subjunctive of the root aorist.