The modal verbs are those verbs which express a mood, such as “like to” or “want to.” The German modal verbs and their basic meanings are:
|dürfen||to be allowed to (in the sense of permission)|
|können||to be able to (in the sense of ability)|
|müssen||to have to|
|mögen||to like to|
|sollen||to be supposed to|
|wollen||to want to|
The modal verbs are irregular in the present tense singular but act like any other verb in the plural. Thus, for example, dürfen conjugates as:
Similarly, the other modal verbs also change their stem in the singular conjugations (except for sollen). In the list below, you will also note that all modal verbs also have no verb ending in the first and third person singular present-tense forms (ich / er / sie / es). As you may recall from Unit 2, wissen is the only non-modal verb that shares this pattern.
The following list demonstrates the irregular singular root of each modal verb and also provides typical translations of each verb:
|dürfen||er darf||he is allowed to / he may / he can|
|können||er kann||he is able to / he can|
|müssen||er muß||he has to / he must / he is required to|
|mögen||er mag||he likes to / he enjoys|
|sollen||er soll||he is supposed to / he should|
|wollen||er will||he wants to|
Amerikaner unter 21 Jahren dürfen keine alkoholischen Getränke kaufen.
Americans unter 21 years may not buy alcoholic drinks.
Wer kann mir helfen?
Who can help me?
Der Student muß fleißig lernen.
The student has to study hard.
Meine Töchter mögen nicht laute Musik hören.
My daughters don’t like to listen to loud music.
Was soll man mit diesem Gerät tun können?
What is one supposed to be able to do with this device?
Mein Sohn will ins Kino gehen.
My son wants to go to the cinema.
In the example above for “sollen,” you can see three verbs. Sollen is conjugated, but tun können are two infinitives. This construction is often called a “double-infinitive.” Translating this into English is simple enough, since the infinitives remain infinitives in English, too.
In general, the dependent infinitive, such as aufräumen or gehen in the examples above, appears in final position in the clause. Note the position of the infinitives in the following example:
Er will nicht sagen, ob er morgen zur Schule gehen muß.
He doesn’t want to say whether he has to go to school tomorrow.
Simple Past Tense
The simple past forms of the modals are formed like regular verbs except that they drop their umlaut. Using the third person singular and plural as our examples:
|dürfen||durfte, durften||(was / were) allowed to|
|können||konnte, konnten||(was / were) able to|
|müssen||mußte, mußten||had to|
|mögen||mochte, mochten||liked to (Note the change from g to ch.)|
|sollen||sollte, sollten||(was / were) supposed to|
|wollen||wollte, wollten||wanted to|
Wir wollten nach Hause gehen.
We wanted to go home.
Der Ingenieur mußte die Maschine reparieren.
The engineer had to repair the machine.
The auxiliary verb of the modals is haben. In the formation of both the present and past perfect tenses of the modal verbs we are introduced to a variation on the “double infinitive” phenomenon. Rather than a past participle, you will see the infinitive form of the modal next to the dependent infinitive.
Die Studentin hat diese ganze Woche fleißig lernen müssen.
The (woman) student has had to study hard this entire week.
Der Ingenieur hatte die Maschine am Sonntag reparieren können.
The engineer had been able to repair the machine on Sunday.
Note that the modal perfect tenses affect the position of the auxiliary verb when it is in a subordinate clause. Instead of appearing at the very end of the clause as usual, it will appear before the double infinitive, and even before an adverb, if there is one. The auxiliary verb is bolded in these examples:
Die Studentin beklagte, daß sie diese ganze Woche hat fleißig lernen müssen.
The (woman) student complained that she has had to study hard this entire week.
Die Fabrik funktionierte weiter, da der Ingenieur die Maschine am Sonntag hatte reparieren können.
The factory continued to function because the engineer had been able to repair the machine on Sunday.
To form the future tense of the modal we use werden and its forms as we do for all future tenses. Thus, using our sentences from the present tense, we have in the future tense:
Der Student wird fleißig lernen müssen.
The student will have to study hard.
Mein Sohn wird ins Kino gehen wollen.
My son will want to go to the cinema.
Again the dependent infinitives go into final position. The difference between the structure of the future and perfect tenses is that the future uses werden and its forms, the perfect tenses haben and its forms.