Germanic weak verb

In the Germanic languages, weak verbs are by far the largest group of verbs, and are therefore often regarded as the norm. They are distinguished from the Germanic strong verbs by the fact that their past tense form is marked by an inflection containing a,, or sound rather than by changing the verb's root vowel.
Whereas the strong verbs are the oldest group of verbs in Germanic, originating in Indo-European, the weak verbs arose as an innovation in Proto-Germanic. Originally the weak verbs consisted of new verbs coined from pre-existing nouns, or coined from strong verbs to express the sense of causing the action denoted by that strong verb.
However, over time, the weak verbs have become the normal form of verbs in all Germanic languages, with most strong verbs being reassigned to the weak class. For example, in Old English the verb to lock was strong, but has now become weak. This transition is ongoing. For example, the English verb to cleave currently exists in both a conservative strong form and an innovative weak form.

General description

In Germanic languages, weak verbs form their preterites and past participles by means of a dental suffix, an inflection that contains a or sound or similar. In all Germanic languages, the preterite and past participle forms of weak verbs are formed from the same stem.

	Infinitive	Preterite
English	to love	loved
English	to laugh	laughed
English	to say	said
English	to send	sent
English	to buy	bought
English	to set	set
German	lieben	liebte
German	bringen	brachte

Historically, the pronunciation of the suffix in the vast majority of weak verbs was but, in most sources discussing Proto-Germanic, it is spelled by convention. In the West Germanic languages, the suffix hardened to, but it remained a fricative in the other early Germanic languages.
In the English language, the dental is a after a voiced consonant or vowel, a after a voiceless consonant, and after the dentals/alveolars and themselves, but English uses the suffix spelling regardless of pronunciation, with the exception of a few verbs with irregular spellings.
In Dutch, and are distributed as in English provided there is a following vowel. When there is no following vowel, terminal devoicing leads to the universal. Nevertheless, Dutch still distinguishes between the spellings in and even in final position: see the 't kofschip rule.
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 German the dental is always and always spelled because of the third phase of the High German consonant shift.
In Low German, the dental ending of the preterite tense was originally or, according to the stem of the verb. However the ending has fallen out in pronunciation, starting in the 17th century when the preterite was written with the ending -er representing the sound, which was already the last remnant of the former -de and -te endings of Middle Low German. Now, the only Low German verbs that still show a remnant of a dental ending are leggen, which has the preterite leed, and 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 but has been hardened to a stop after nasals and. It and has been devoiced to after voiceless consonants and in some other cases. Furthermore, the voicing contrast between and 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 in which it remains, the dental is or, depending on conjugation class and dialect. It is spelled accordingly. In Nynorsk, it can be different in the preterite and the past participle.
Swedish has a similar situation to that of Norwegian, but the dental is retained in the spelling, even between vowels. Some informal spellings indicate a lost dental, such as in sa from the standard spelling sade.

Classes of verbs

In Proto-Germanic, there were seven types of weak verbs, five of which were common. However, they are normally grouped into four classes, based on the conjugational system of Gothic.

Class I verbs

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

Class I, subclass (i)

A small class of verbs had no suffix in the present, and no suffix in the past. This class had only three members:

*bringaną "to bring", past tense *branht-. This verb was continued as such in all the descendants, although an alternate stem *brangij- occasionally appeared in some of the West Germanic languages.
*brūkaną "to use", past tense *brūht-. This verb tended to move into other classes. For example, in Gothic this verb moved into subclass of Class I, whereas in Old English it became a Class II strong verb.
*būaną "to dwell", past tense *būd-. This verb continued as such in most descendants but became a Class III weak verb bauan in Gothic.
Class I, subclass (ii)

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:

*bugjaną "to buy," past tense *buht-
*sōkijaną "to seek," past tense *sōht-
*þankijaną "to think," past tense *þanht-
*þunkijaną "to seem," past tense *þunht-
*wurkijaną "to work," past tense *wurht-

Verbs of this class were said to undergo rückumlaut in the past, since the umlaut occurring in the present is undone or "reversed" in the past, 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. Specifically:

There is an alternation between -k- or -g- in the present and -h- in the past, caused by the -t- of the past-tense suffix. Prior to the operation of Grimm's Law, the stem consonant was -g- or -gʰ-. Before -t-, the consonant was devoiced to -k- by assimilation and then became -h- by Grimm's Law. This alternation is sometimes called Primärberührung.
-n- before -h- disappeared after nasalizing the previous vowel. When the -n- disappeared, the vowel was lengthened by the process of compensatory lengthening.
-u- was lowered to -o- in the past tense due to a-mutation, since the following vowel was always non-high.

The class remained small in Gothic, but expanded significantly in the other languages:

In Old Norse, all short-stem verbs appeared to move into this class, as indicated by the fact that no umlaut occurs in the past, as would be caused by a suffix -i-. However, this may have been due to a regular sound change that eliminated unstressed, nonfinal short vowels coming after a short stem before the operation of umlaut.
In Old High German, short-stem verbs ending in -zz, -pf, -ck, and optionally those in -ll, join this class. For example, zellen "to tell" < *taljan, past tense zalta, zelita. A number of long-stem verbs also join this class, like brennen "to burn," past tense branta; wenten "to turn," past tense wanta.
In Old English and the other northern West Germanic languages, a number of verbs ending in -c- and -ll- joined the class, including the following Old English verbs:

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, as in the new past tense form cwehte alongside earlier cweahte.

Class I, subclass (iii)

A large class of verbs had the suffix -j- in the present and -i- in the past, for example, Gothic satjan "to set" and sandjan "to send". As shown in the Old English cognates:

The -j- produced umlaut of the stem vowel in languages other than Gothic.
The -j- caused West Germanic gemination in the West Germanic languages in short-stem verbs ending in a consonant other than -r.
The -j- resulted in palatalization of preceding velar consonants in Old English.
The -j- remained in Gothic and Old Saxon, but disappeared in the other languages: In long-stem verbs in Old Norse, and in all verbs except those in -r in the remaining West Germanic languages.

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, 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". Note that the Old Saxon and Old Frisian verbs given here are unattested, almost certainly due to the small nature of the respective corpora.
The following is a cross-language paradigm of a long-stem Class I verb *hauzijaną "to hear"