1.All the verbal forms were built from 4 principle forms of the verb in OE.They were Present, Past sg, Past pl, Participle II. Following the way they built their forms OE verbs fell into 3 subdivisions: strong, weak, minor.(strong, weak verbs ЦGrim).
The main differences between weak and strong verbs are the following:
1) Strong verbs formed their past tense by means of (changing the root vowel without adding any suffix). Weak verbs formed their past tense by means of a special dental suffix, as a rule there was no vowel interchange.
2) Strong verbs formed their Part II by adding the suffix Цen and vowel interchange.
3)Weak verbs fell into 3 classes (according to the stem-building suffix); strong verbs fell into 7 classes according to the vowel interchange in the root.
In addition to weak and strong verbs there were minor groups of verbs: Preterite Ц Present verbs; Suppletive verbs; Irregular or Anomalous verbs.
In OE there were about 300 strong verbs. They did not show any tendency to increase in number.
2. OE strong verbs were divided into 7 classes. Each class had a peculiar vowel gradation, which went back to the Indo-European ablaut (ĕ─ŏ). Vowel interchange was later modified in Proto Germanic. (OE ŏ→PG ǎ).
ĕ─ŏ Ц qualitative ablaut
Ø Ц нулевой or zero ablaut (беру, брал).
ĕ - a front vowel, ŏ - a back v, Ø - a zero v.
↓ (в др. герм. пер.
æ a o носовыми)
ē Ø u
↓ ↓ ↓
ǽ Ø u
Ex. ¬ставной u
The original IE vowel gradation series split into several serious because the gradation vowel was inserted in the root and was combined there (?in the sound of the root?).
The gradation series used in classes 1-5 go back to the IE qualitative ablaut ĕ─ŏ.
In this class the gradation vowel was combined with short i in the root, as a result we find long vowels in the first two forms and short i in the zero grade.
a-stem Past sg
Past pl 3 ф.
In this class the gradation vowel was combined with u-vowel of the root. Long diphthongs in the first two forms and u in the zero grade.
IE e/i + u
u remained before- n (nasal) -i/j, o - in other cases.
To this class belong all strong verbs in which the root was followed by a sonant + one more consonant. e-o- Ø
In this class the root was followed by a consonant.
To this class belong the strong verbs in which the root was followed by a noise consonant.
In this class the original IE gradation was quantitative (short, long). In PG it was transformed into a qualitative-quantitative series.
The strong verbs of this gram class built their forms by reduplication (doubling) of the root syllable. Both the consonant and vowel were doubled.
Gth haitan haihait haihaitum haitans (call)
OE hātan hāitans heht
In OE the direct traces of reduplications were very rare, only a few verbs of the class remained ?and then lost?.