Old English verbs come in two main types: strong and weak. Strong verbs change their stem vowel to show past tense (a process called ablaut), while weak verbs add a dental suffix instead. This distinction is fundamental to Old English grammar, and traces of it survive in Modern English (think sing/sang/sung vs. walk/walked).
Strong verbs are the older type, inherited from Proto-Germanic. Weak verbs developed later as a more regular, predictable way to conjugate. Over time, many strong verbs shifted to weak conjugation, a trend toward simplification that continued well into Middle English and beyond.
Strong and Weak Verbs in Old English
Features of Old English Verbs
Strong verbs form the past tense through ablaut, which means the vowel inside the verb stem changes. No suffix is added. Because they come from Proto-Germanic, they represent an older layer of the language. A Modern English example of this surviving pattern: drive/drove/driven.
Weak verbs form the past tense by adding a dental suffix (-d, -t, or -ed) to the verb stem. The stem vowel stays the same throughout conjugation. These developed later in the history of Germanic languages and became the default class for new verbs entering the language. Most Modern English verbs follow this pattern: judge/judged, walk/walked.
Conjugation of Regular Verbs
Here's how a strong verb and a weak verb each conjugate across present and past tense. Pay attention to where the vowel changes in the strong verb and where the suffix appears in the weak verb.
Strong verb: drīfan (to drive)
- Present tense: drīfe (I drive), drīfst (you drive), drīfþ (he/she/it drives), drīfaþ (we/they drive)
- Past tense: drāf (I/he/she/it drove), drife (you drove), drifon (we/they drove)
Notice how the stem vowel shifts from ī in the present to ā (past singular) and i (past plural). No suffix is added.
Weak verb: dēman (to judge)
- Present tense: dēme (I judge), dēmst (you judge), dēmþ (he/she/it judges), dēmaþ (we/they judge)
- Past tense: dēmde (I/he/she/it judged), dēmdest (you judged), dēmdon (we/they judged)
The stem vowel ē stays constant throughout. The past tense is marked by the -d- suffix inserted before the personal ending.
Patterns of Ablaut
Strong verbs are organized into seven classes based on their vowel gradation pattern. Each class has four principal parts: the infinitive, the past singular, the past plural, and the past participle. Learning these four forms for each class lets you conjugate any strong verb in that group.
- Class I: ī → ā → i → i
- wrītan (to write): wrītan, wrāt, writon, writen
- Class II: ēo → ēa → u → o
- bēodan (to offer): bēodan, bēad, budon, boden
- Class III: e/i → a → u → o/u
- helpan (to help): helpan, healp, hulpon, holpen
- Class IV: e → æ → ǣ → o
- beran (to bear): beran, bær, bǣron, boren
- Class V: e → æ → ǣ → e
- metan (to measure): metan, mæt, mǣton, meten
- Class VI: a → ō → ō → a
- faran (to go/travel): faran, fōr, fōron, faren
- Class VII: various patterns (reduplicating verbs)
- cnāwan (to know): cnāwan, cnēow, cnēowon, cnāwen
Classes IV and V look similar, so watch the past participle to tell them apart: Class IV ends in -o- (boren), while Class V returns to -e- (meten). Class VII is the trickiest because it doesn't follow a single vowel pattern; these verbs historically used reduplication (repeating part of the stem), though by the Old English period this had mostly been replaced by vowel changes.
Historical Development of Strong and Weak Verbs
Origins of Verb Systems
Strong verbs were inherited directly from Proto-Germanic. Their ablaut system traces back even further to the Indo-European perfect tense, which originally expressed completed actions. Over the centuries, the number of strong verbs gradually shrank as speakers regularized them into weak conjugation.
Weak verbs developed later as a Germanic innovation. The dental suffix is thought to derive from the Proto-Germanic verb *dōną ("to do"), essentially creating a compound construction that became fused into a single word over time. Because the weak pattern was regular and predictable, it became the productive class: virtually all new verbs coined or borrowed into the language entered as weak verbs. This regularization pressure is why so many originally strong verbs eventually shifted to weak conjugation, a process that continued through Middle English and into the modern language.