ModalverbenModal verbs

Modal verbs go with an infinitive and indicate how an action is meant. They express permission, ability, preference, necessity, recommendation, or wish, and thereby alter the meaning of the sentence. In a sentence they carry the main grammatical load, while the finite verb infinitive states the actual action. For an overview of auxiliary verbs, 'auxiliary verbs' is useful, and for the form of the second verb the Infinitive.

Dürfen expresses permission and is used when something is allowed. It belongs to the strong modal verbs and combines with an infinitive in the sentence. In the Perfekt and in other compound forms it appears with a double infinitive, which is also common with other modal verbs.

Können expresses ability and possibility. It describes what a person can do or what is possible under the given circumstances. As a modal verb it goes with the infinitive of the main verb and forms compound tenses with the infinitive of the main verb and the participle or auxiliary-verb part, not alone, but as part of the modal-verb pattern.

Mögen expresses a preference and designates what someone likes. In everyday life it is often confused with möchten, which is a polite wish form from Konjunktiv II. Mögen appears with an infinitive only in certain uses, while the most common meaning is a direct preference for things or people.

Müssen shows necessity and compulsion. It is used when an action is necessary or cannot be avoided. In combination with the infinitive the main verb remains unchanged, and in the Perfekt the typical compound forms of modal verbs appear.

Sollen expresses recommendation, expectation or instruction. It is often used when another party demands or suggests an action. The verb combines with the infinitive and often appears in command-like statements as an indirect instruction, which is also interesting in connection with the Imperative.

Wollen expresses desire and intention. It shows what someone intends or actively pursues, and is therefore often close to direct statements about plans. In the Perfekt and in other compound tenses it follows the same periphrastic patterns as the other modal verbs.

Weak verbs form the personal forms regularly with the stem and the endings -e, -st, -t and -en. The stem vowel normally stays the same in the present, and the pattern is the basic conjugation form for many common verbs. The infinitive also remains closely tied to this regular pattern with -en or -n.

Strong verbs often show a vowel change in the stem and form the simple past (Präteritum) irregularly. They do not follow a uniform ending pattern in the past stem, but must be learned in their forms. A typical example is fahren, which forms fuhr in the simple past, thus clearly showing the strong stem change.

Mixed verbs combine a stem change with a regular simple past ending. They thus appear partly strong and partly weak and form in the simple past usually the ending -te. A common example is bringen, which in the simple past is brachte, thereby clearly showing the mixed form.

The infinitive usually ends in -en or -n and denotes the pure verb form without person. The Partizip II is often formed with ge- plus stem plus -t or -en and is important for the Perfekt and other compound tenses. With separable and inseparable prefixes as well as regional variants, the form can vary, but the basic pattern remains recognizable for many verbs.

In compound tenses modal verbs often appear with a second infinitive, so the infinitive of the main verb appears together with the modal verb. In the Perfekt, this is the typical double infinitive structure with the auxiliary and two infinitives, and in the passive, modal verbs combine with passive constructions to form more complex sentences. These patterns are especially important when modal verbs occur in the past or in formal sentence constructions.

The earliest and most common modal verbs are dürfen, können, müssen, sollen and wollen, because they are used constantly in everyday life. Mögen serves as the verb of preference and is particularly important for firm opinions and expressions of taste. Together they form a core area of the German verb system, which is also fundamental for the Infinitive, Participles, Present Perfect, Subjunctive II, and Imperative.