In Germanic languages, including English, weak verbs are by far the largest group of verbs, which are therefore often regarded as the norm (the regular verbs), though historically they are not the oldest or most original group.
In Germanic languages, weak verbs are those verbs that form their preterites and past participles by means of a dental suffix, an inflection that contains a /t/ or /d/ sound or similar. (For comparative purposes we may refer to this generally as a dental, although in some of the languages, including most varieties of English, /t/ and /d/ are alveolar rather than dental consonants.) In all Germanic languages, the preterite and past participle forms of weak verbs are formed from the same stem. For example:
|English (regular)||to love||loved||loved|
|English (irregular)||to say||said||said|
Historically, the pronunciation of the suffix in the vast majority of weak verbs (all four classes) was, although in most sources discussing Proto-Germanic it is spelled
In English, the dental is a /d/ after a voiced consonant (loved) or vowel (laid), and a /t/ after a voiceless consonant (laughed), though English uses the spelling in
In Dutch, /t/ and /d/ are distributed as in English provided there is a following vowel, but when there is no following vowel, terminal devoicing causes the pronunciation /t/ in all cases. Nevertheless, Dutch does distinguish the spellings in
In Afrikaans, which descends from Dutch, the past tense has fallen out of use altogether, and the past participle is marked only with the prefix ge-. Therefore, the suffix has disappeared along with the forms that originally contained it.
In Low German, the dental ending of the preterite tense was originally in /d/ or /t/ according to the stem of the verb. However this ending has fallen out in pronunciation, starting in the 17th century when the preterite was written with an ending -er representing the sound [ɐ] which was already the last remain of the former -de and -te endings of Middle Low German. Nowadays the only Low German verb that still shows a remnant of dental ending is leggen which has the preterite leed . The verb hebben which has harr with old r-ending from the Middle Low German dental.
In Icelandic, the dental was originally a voiced dental fricative ; it is preserved as such after vowels, voiced fricatives and /r/, but has been hardened to a stop /d/ after nasals and /l/, and has been devoiced to /t/ after voiceless consonants and in some other cases (in most Old Norse texts, this alternation is already found in heavy roots, although the light ones preserve /ð/). Furthermore, the voicing contrast between /d/ and /t/ has been replaced in Modern Icelandic by an aspiration contrast, which may not be realized phonetically in all the relevant positions.
The situation of early Norwegian was similar to Icelandic, but intervocalic eventually disappeared. In the verbs where it remains, the dental is /t/, /d/, depending on conjugation class and dialect. It is spelled accordingly. In Nynorsk, it can be different in the preterite and the past participle.
Swedish is very similar to Norwegian, although the dental is retained in the spelling, even between vowels. Some informal spellings indicate a lost dental, such as in sa ("said") from the standard spelling sade.
In Proto-Germanic, there were seven types of weak verbs, five of which were significant. However, they are normally grouped into four classes, based on the conjugational system of Gothic.
Class I verbs actually consist of three classes in Proto-Germanic:
A small class of verbs had no suffix in the present, and no suffix in the past (other than the -d- or -t- of all weak verbs). This class had only three members:
A small class of verbs had the suffix -j- in the present and no suffix in the past. This class had only five members in Proto-Germanic:
Verbs of this class are said to undergo rückumlaut ("reverse umlaut") in the past, since the umlaut occurring in the present (triggered by the -j-) is undone or "reversed" in the past (due to the lack of the umlaut-triggering stem -i- of subclass (iii)), leading to a non-umlauted vowel in the past.
These verbs also have consonant and vowel alternations between present and past that are due to regular sound changes but result in strikingly different forms in the historical Germanic languages (e.g. think, past tense thought). Specifically:
The class remained small in Gothic, but expanded significantly in the other languages:
In Late Old English, further verbs in -can were drawn into this class by analogy, but with umlaut maintained, e.g. bepǣcan "to deceive", past tense bepǣhte, earlier bepǣcte, or wleccan "to warm", past tense wlehte, earlier wlecede. At the same time, verbs in -ccan were modified to follow the same pattern, e.g. new past tense cwehte alongside earlier cweahte.
A large class of verbs had the suffix -j- in the present and -i- in the past: e.g. Gothic satjan "to set" (Old English settan), sandjan "to send" (Old English sendan). As shown in the Old English cognates:
This class was split into two subclasses in all the Old Germanic languages, one consisting of short-stem verbs and one of long-stem verbs. The distinction between the two was originally due to Sievers' Law, and was extended due to changes such as West Germanic gemination, which affected short-stem but not long-stem verbs. The West Germanic languages had a third subclass consisting of short-stem verbs ending in -r (e.g. Old English erian "to plow", nerian "to save", styrian "to stir"), due to West Germanic gemination and subsequent loss of -j- not taking place.
The following is a cross-language paradigm of a short-stem Class I verb *gramjaną "to anger" (Gothic gramjan, Old Norse gremja, Old High German gremmen, Old Saxon *gremmian, Old English gremman, Old Frisian *gremma). Note that the Old Saxon and Old Frisian verbs given here are unattested, almost certainly due to the small nature of the respective corpora.
|Gothic||Old Norse||Old High German||Old Saxon||Old English||Old Frisian|
|Pres. 1pl.||gramjam||gremjum||gremmemēs (-ēn)||gremmiad||gremmaþ||gremmath|
|Pres. Subj. 1sg.||gramjáu||gremja||gremme||gremmia (-ie)||gremme||gremme|
|Pres. Subj. 2sg.||gramjáis||gremir||gremmēs(t)||gremmias (-ies)||gremme||gremme|
|Pres. Subj. 3sg.||gramjái||gremi||gremme||gremmia (-ie)||gremme||gremme|
|Pres. Subj. 1du.||gramjáiwa||--||--||--||--||--|
|Pres. Subj. 2du.||gramjáits||--||--||--||--||--|
|Pres. Subj. 1pl.||gramjáima||gremim||gremmēm (-ēn, -ēmēs)||gremmian||gremmen||gremme|
|Pres. Subj. 2pl.||gramjáiþ||gremið||gremmēt||gremmian||gremmen||gremme|
|Pres. Subj. 3pl.||gramjáina||gremi||gremmēn||gremmian||gremmen||gremme|
|Past 1pl.||gramidēdum||grǫmdum||gremitum (-un, -umēs)||gremidun||gremedon||gremedon|
|Past Subj. 1sg.||gramidēdjáu||gremda||gremiti (-ī)||gremidi||gremede||gremede|
|Past Subj. 2sg.||gramidēdeis||gremdir||gremitīs(t)||gremidīs||gremede||gremede|
|Past Subj. 3sg.||gramidēdi||gremdi||gremiti (-ī)||gremidi||gremede||gremede|
|Past Subj. 1du.||gramidēdeiwa||--||--||--||--||--|
|Past Subj. 2du.||gramidēdeits||--||--||--||--||--|
|Past Subj. 1pl.||gramidēdeima||gremdim||gremitīm (-īn, -īmēs)||gremidīn||gremeden||gremede|
|Past Subj. 2pl.||gramidēdeiþ||gremdið||gremitīt||gremidīn||gremeden||gremede|
|Past Subj. 3pl.||gramidēdeina||gremdi||gremitīn||gremidīn||gremeden||gremede|
|Imper. 1pl.||gramjam||gremjum||gremmemēs (-ēn)||--||--||--|
The following is a cross-language paradigm of a long-stem Class I verb *hauzijaną "to hear" (Gothic hausjan, Old Norse heyra, Old High German hōren, Old Saxon hōrian, Old English hīeran, Old Frisian hēra)
|Gothic||Old Norse||Old High German||Old Saxon||Old English||Old Frisian|
|Pres. 1pl.||hausjam||heyrum||hōremēs (-ēn)||hōriad||hīeraþ||hērath|
|Pres. Subj. 1sg.||hausjáu||heyra||hōre||hōria (-ie)||hīere||hēri (-e)|
|Pres. Subj. 2sg.||hausjáis||heyrir||hōrēs(t)||hōrias (-ies)||hīere||hēri (-e)|
|Pres. Subj. 3sg.||hausjái||heyri||hōre||hōria (-ie)||hīere||hēri (-e)|
|Pres. Subj. 1du.||hausjáiwa||--||--||--||--||--|
|Pres. Subj. 2du.||hausjáits||--||--||--||--||--|
|Pres. Subj. 1pl.||hausjáima||heyrim||hōrēm (-ēn, -ēmēs)||hōrian||hīeren||hēri (-e)|
|Pres. Subj. 2pl.||hausjáiþ||heyrið||hōrēt||hōrian||hīeren||hēri (-e)|
|Pres. Subj. 3pl.||hausjáina||heyri||hōrēn||hōrian||hīeren||hēri (-e)|
|Past 1pl.||hausidēdum||heyrðum||hōrtum (-un, -umēs)||hōrdun||hīerdon||hērdon|
|Past Subj. 1sg.||hausidēdjáu||heyrða||hōrti (-ī)||hōrdi||hīerde||hērde|
|Past Subj. 2sg.||hausidēdeis||heyrðir||hōrtīs(t)||hōrdīs||hīerde||hērde|
|Past Subj. 3sg.||hausidēdi||heyrði||hōrti (-ī)||hōrdi||hīerde||hērde|
|Past Subj. 1du.||hausidēdeiwa||--||--||--||--||--|
|Past Subj. 2du.||hausidēdeits||--||--||--||--||--|
|Past Subj. 1pl.||hausidēdeima||heyrðim||hōrtīm (-īn, -īmēs)||hōrdīn||hīerden||hērde|
|Past Subj. 2pl.||hausidēdeiþ||heyrðið||hōrtīt||hōrdīn||hīerden||hērde|
|Past Subj. 3pl.||hausidēdeina||heyrði||hōrtīn||hōrdīn||hīerden||hērde|
|Imper. 1pl.||hausjam||heyrum||hōremēs (-ēn)||--||--||--|
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).
|Gothic||Old Norse||Old High German||Old Saxon||Old English||Old Frisian|
|Infinitive||laþōn||laða||ladōn, lathōn||lathian (-ōjan), ladian (-ōjan)||laþian||lathia|
|Pres. 1sg.||laþō||laða||ladōm (-ōn), lathōm (-ōn)||lathōn, ladōn||laþie||lathie|
|Pres. 2sg.||laþōs||laðar||ladōs(t), lathōs(t)||lathōs, ladōs||laþast||lathast (-est)|
|Pres. 3sg.||laþōþ||laðar||ladōt, lathōt||lathōd, ladōd||laþaþ||lathath|
|Pres. 1pl.||laþōm||lǫðum||ladōmēs (-ōn), lathōmēs (-ōn)||lathōd (-ōjad), ladōd (-ōjad)||laþiaþ||lathiath|
|Pres. 2pl.||laþōþ||laðið||ladōt, lathōt||lathōd (-ōjad), ladōd (-ōjad)||laþiaþ||lathiath|
|Pres. 3pl.||laþōnd||laða||ladōnt, lathōnt||lathōd (-ōjad), ladōd (-ōjad)||laþiaþ||lathiath|
|Pres. Subj. 1sg.||laþō||laða||lado, latho||lathō (-ōja), ladō (-ōja)||laþie||lathie|
|Pres. Subj. 2sg.||laþōs||laðir||ladōs(t), lathōs(t)||lathōs (-ōjes), ladōs (-ōjes)||laþie||lathie|
|Pres. Subj. 3sg.||laþō||laði||lado, latho||lathō (-ōja), ladō (-ōja)||laþie||lathie|
|Pres. Subj. 1du.||laþōwa||--||--||--||--||--|
|Pres. Subj. 2du.||laþōts||--||--||--||--||--|
|Pres. Subj. 1pl.||laþōma||laðim||ladōm (-ōn, -ōmēs), lathōm (-ōn, -ōmēs)||lathōn, ladōn||laþien||lathie|
|Pres. Subj. 2pl.||laþōþ||laðið||ladōt, lathōt||lathōn, ladōn||laþien||lathie|
|Pres. Subj. 3pl.||laþōna||laði||ladōn, lathōn||lathōn, ladōn||laþien||lathie|
|Past 1sg.||laþōda||laðaða||ladōta, lathōta||lathōda, ladōda||laþode||lathade|
|Past 2sg.||laþōdēs||laðaðir||ladōtōs(t), lathōtōs(t)||lathōdōs, ladōdōs||laþodest|
|Past 3sg.||laþōda||laðaði||ladōta, lathōta||lathōda, ladōda||laþode||lathade|
|Past 1pl.||laþōdēdum||lǫðuðum||ladōtum (-un, -umēs), lathōtum (-un, -umēs)||lathōdun, ladōdun||laþodon||lathadon|
|Past 2pl.||laþōdēduþ||lǫðuðuð||ladōtut, lathōtut||lathōdun, ladōdun||laþodon||lathadon|
|Past 3pl.||laþōdēdun||lǫðuðu||ladōtun, lathōtun||lathōdun, ladōdun||laþodon||lathadon|
|Past Subj. 1sg.||laþōdēdjáu||laðaða||ladōti (-ī), lathōti (-ī)||lathōda, ladōda||laþode|
|Past Subj. 2sg.||laþōdēdeis||laðaðir||ladōtīs(t), lathōtīs(t)||lathōdōs, ladōdōs||laþode|
|Past Subj. 3sg.||laþōdēdi||laðaði||ladōti (-ī), lathōti (-ī)||lathōda, ladōda||laþode||lathade|
|Past Subj. 1du.||laþōdēdeiwa||--||--||--||--||--|
|Past Subj. 2du.||laþōdēdeits||--||--||--||--||--|
|Past Subj. 1pl.||laþōdēdeima||laðaðim||ladōtīm (-īn, -īmēs), lathōtīm (-īn, -īmēs)||lathōdun, ladōdun||laþoden||lathade|
|Past Subj. 2pl.||laþōdēdeiþ||laðaðið||ladōtīt, lathōtīt||lathōdun, ladōdun||laþoden||lathade|
|Past Subj. 3pl.||laþōdēdeina||laðaði||ladōtīn, lathōtīn||lathōdun, ladōdun||laþoden||lathade|
|Imper. 2sg.||laþō||laða||lado, latho||lathō, ladō||laþa|
|Imper. 1pl.||laþōm||lǫðum||ladōmēs (-ōn), lathōmēs (-ōn)||--||--||--|
|Imper. 2pl.||laþōþ||laðið||ladōt, lathōt||lathōd, ladōd||laþiaþ|
|Pres. Participle||laþōnds||laðandi||ladōnti, lathōnti||lathōnd (-ōjand), ladōnd (-ōjand)||laþiende||lath(i)ande|
|Past Participle||laþōþs||laðaðr||ladōt, lathōt||lathōd, ladōd||laþod||lathad|
What is known as "Class III" was actually two separate classes in Proto-Germanic:
The histories of this class in the various Germanic languages are quite varied:
An example is the stative verb reconstructed as Proto-Germanic *habjaną "to have", past indicative third-person singular habdē:
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:
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, e.g. 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, i.e. "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, since they are formed to other verbs (which are in turn formed off of 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, e.g. 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").
In the modern languages, the various classes have mostly been leveled into a single productive class. Icelandic, Norwegian and Frisian have retained two productive classes of weak verbs. (In Frisian, in addition to the class with -de, there is a class of je-verbs, where the dental suffix has dropped, i.e. -je < -iad.) Swiss German also has two types of weak verbs, descended from Class I and Classes II and III respectively of Old High German weak verbs and marked with -t and -et, respectively, in the past participle.
In the history of English, the following changes happened:
In Modern English, only one productive weak paradigm remains, derived from Class II. A number of Class I verbs still persist, e.g.:
As the previous list shows, although there is only one productive class of weak verbs, there are plenty of "irregular" weak verbs that don't follow the paradigm of this class. Furthermore, the regular paradigm in English is not unitary, but in fact is divided into subclasses in both the written and spoken language, although in different ways:
Both of these characteristics occur in a similar fashion in most or all the modern Germanic languages. In modern German, for example, descendants of the original subclass (ii) of Class I are still irregular (e.g. denken (dachte) "to think", brennen (brannte) "to burn"), and subclasses of the productive verb paradigm are formed by verbs ending in -eln or -ern and in -ten or -den, among others.
One of the regular weak verb conjugations is as follows.
|English||West Frisian||Afrikaans||Dutch||Low German||German||Yiddish|
|Infinitive||work||wurkje||leare 2||werk 1||werken||warken||werken||(verkn) װערקן|
|present||I work |
|ik wurkje |
|ik lear |
|ek werk |
|ik werk |
|ik wark |
|ich werke |
|(ikh verk) איך װערק |
(du verkst) דו װערקסט
(er verkt) ער װערקט
(mir verkn) מיר װערקן
(ir verkt) איר װערקט
(zey verkn) זי װערקן
|Preterite||I worked |
|ik wurke |
|ik learde |
|(not used)||ik werkte |
|ik wark |
|ich werkte |
|Past participle||worked||wurke||leard||gewerk||gewerkt||(ge)warkt||gewerkt||(geverkt) געװערקט|
1. The distinction between the infinitive and present forms of Afrikaans verbs has been lost with the exception of a very few such as wees and is, "to be" and "is/am/are"
2. learn, teach
|Swedish||Danish||Norwegian Bokmål||Norwegian Nynorsk||Icelandic||Faroese|
|present||jag verkar |
|jeg virker |
|jeg virker |
|eg verkar |
|ég verka |
|eg virki |
|Preterite||jag verkade |
|jeg virkede |
|jeg virket/virka |
|eg verka |
|ég verkaði |
|eg virkaði |
3. prepare, manufacture
Weak verbs should be contrasted with strong verbs, which form their past tenses by means of ablaut (vowel gradation: sing - sang - sung). Most verbs in the early stages of the Germanic languages were strong. However, as the ablaut system is no longer productive except in rare cases of analogy, almost all new verbs in Germanic languages are weak, and the majority of the original strong verbs have become weak by analogy.
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:
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. These verbs may be thought of as "semi-strong" (not a technical term). Dutch has a number of examples of this:
An example in English is:
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).
The reverse process is also possible, though very rare: verbs which were originally weak can become strong by analogy. This can also be partial, producing "semi-strong" verbs:
Weak verbs which develop strong forms are often unstable. A typical example is German fragen (to ask), which is historically weak, and still weak in Standard German, but 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 in some dialects gevrogen is used).
The weak conjugation of verbs is an innovation of Proto-Germanic (unlike the older strong verbs, the basis of which goes back to Proto-Indo-European). While primary verbs (those inherited from PIE) already had an ablaut-based perfect form which was the basis of the Germanic strong preterite, secondary verbs (those derived from other forms after the break-up of PIE) had to form a preterite otherwise; this necessitated the creation of the weak conjugation.
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 which 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'.
A significant subclass of Class I weak verbs are (deverbal) causative verbs. These 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). Examples:
Essentially all verbs formed this way were conjugated as Class I weak verbs.
This 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 recognize. For example, rear is the regular phonological development of Proto-Gemanic *raizijaną given in the above list, but the connection between rise and rear is no longer obvious. (raise is a later, analogical development.) As another example, drench was originally the causative of drink, but the modern meaning of "drench" (i.e. "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.
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 were therefore unable to show the ablaut distinction necessary for a strong preterite. This was the case with the verbs waurkjan 'to work, create', bugjan 'to buy', and sokjan 'to seek' (Gothic forms).
Preterite-present verbs are primary verbs in which the PIE present was lost, and the perfect was given a present meaning. These needed a new past tense, which followed the weak pattern.
All borrowings from other languages into Germanic were weak.
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 *lubōda dēdē ("love-did") > *lubōdē > Old English lufode > loved or *salbō-dē- ("salve-did", i.e., "put salve") > *salbōdē- > Old English sealfode > salved. This would be analogous to the way that in Modern English we 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 as such did not take a perfect. It did, however, take a reduplicating present. The imperfect of this root is taken by many to be the origin of the dental suffix.
|Periphrastic origin of dental suffix||PIE imperfect of "do"||Proto-Germanic imperfect of "do"||Gothic weak preterite ending|
This view is not without objections. These are two often-proposed difficulties with this explanation:
These objections are sometimes answered as follows:
Another theory is that it came from a past participle ending, a final *-daz from PIE *-tos (cf Latin amatus), with personal endings added to it at a later stage. This theory 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.
The term "weak verb" was originally coined by Jacob Grimm and in his sense refers only to Germanic philology. However, the term is sometimes applied to other language groups to designate phenomena which are not really analogous. For example, Hebrew irregular verbs are sometimes called weak verbs because one of their radicals is weak. See: weak inflection.