Modal Auxiliary Verbs

Modal verbs are a particular class of auxiliary verbs that express necessity, possibility, intention, permission, or ability. Modern verbs like 'must', 'should' and 'can', are almost all descended from Old English, so they should be easy to recognise, but before we begin we need to make clear what distinguishes auxiliary verbs from normal verbs.

Auxiliary Verbs

Auxiliary verbs are 'helping' verbs that combine with a main verb to make meaning. In modern English we use auxiliary verbs such as 'to have' to form various tenses (for example, in the sentence 'I have seen'), and auxiliaries such as 'to be' to express the passive voice (for example, in the sentence 'The window was broken').

Modal Verbs

The modal verbs in modern English are must, shall, will, should, would, can, could, ought (to), may, and might. They are used with a main verb to express an obligation (I must go), an intention (I will go), an ability (I can go), a permission (I may go), and so on. The most useful Old English modal auxiliaries are listed in the table below.

As you can see, some of the modern English modals come from the same Old English verb in its past and present forms: so the verb 'sculan' is the basis of modern English 'shall' and 'should'.

Preterite-Present Verbs

As you might remember from the Irregular Verbs module, 'willan' is an irregular verb, but generally Old English modal auxiliaries are preterite-present verbs. These verbs are a little different to strong and weak verbs.

Preterite present verb have an -on ending in the present plural, as opposed to the -að ending present in both strong and weak present plural verbs. They form their past tense using a dental suffix (-d or -t), like weak verbs. Finally, the vowel in the stem changes often changes even in the present tense. For example, 'sculan - shall' becomes 'ic sceal - I shall' and 'ic scolde - I should'. Examine the sentences below: 'Hwæt sceal ic don? - What shall/should I do?' and 'Eal folc scolde fæsten ðri dagas - All folk should fast for three days'.

Using Modal Verbs

In simple constructions, modal auxiliaries are followed by an infinitive verb. To recap, the infinitive is the base form of a verb, which ends in -an in Old English. Modal auxiliary + infinitive constructions such as 'Ic cann rune writan - I can write runes' or 'Heo mæg me gehælan - She may heal me' behave in exactly the same way as in modern English, as the modal verb is followed by the main verb in the infinitive.

Auxiliary + Infinitive Word Order

One thing worth looking out for when encountering modal auxiliaries is that the infinitive verb that follows a auxiliary often goes to the very end of the clause or sentence. The key thing is to remember that when a modal (or any auxiliary verb) is being used, you should look for the verb that it is helping. For example, in the sentence 'Cyning sceal on healle beagas dælan - A king should distribute rings in the hall', the auxiliary 'sceal' needs a main verb, which in this case is 'dælan'.

Finally, it is worth mentioning that although the verb 'to do' was used regularly in Old English, it was not used as an auixiliary in the formation of questions or negations as it is in modern English. So we would find 'He swa dyde - he did so', but 'Dranc he? rather than 'did he drink?' and 'ne dranc he' rather than 'he didn't drink'.

Use the table below to practice the questions, or hide it if you're confident you understand how they work. Otherwise, continue to the inflected infinitive.

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