Modal verbs usually modify another verb in the sentence - the main verb. They provide more information about the nature of the action expressed by the main verb. You have learned all about the modal verbs "können", "müssen", "sollen", "dürfen", "wollen" and "möchten".

Modal verbs are irregular, but their endings in the 1st and 3rd person singular and in the 1st and 3rd person plural are identical respectively. Here is an overview of their conjugation in the present tense:
 

The modal verbs change the meaning of a sentence.

Example:
Ihr spielt mit dem Pinguin. = The children are playing with the penguin.
Ihr dürft mit dem Pinguin spielen. = The children have permission to play with the penguin.

The modal verbs are used in the following situations:

"können" indicates the ability or opportunity to do something.

Examples:
Harry kann Deutsch sprechen.
= Harry has learned German and can (has the ability to) speak the language.
Sie können gerne ein anderes Zimmer haben.
= You are welcome to have a different room. You can have a different room.
 

"dürfen" gives permission to do something.

Examples:
Der Pinguin darf bleiben, aber nur eine Nacht.
= The penguin may stay for one night.
Dürfen wir mit dem Pinguin spielen?
= Are we allowed to / may we play with the penguin?

"dürfen" + negation means that someone does not have the permission / may not do something.

Examples:
Pinguine dürfen nicht im Hotel übernachten.
= Penguins are not allowed to stay in the hotel.
Der Pinguin darf nicht bleiben.
= The penguin may not stay. The hotelier prohibits it.
 

"müssen" indicates an order or necessity.

Examples:
Der Pinguin muss das Hotel verlassen.
= The hotelier demands that the penguin be removed from the hotel.
Ich muss jetzt gehen.
= I have to go now.
 

"sollen" means should or ought to.
It denotes a challenge or strong recommendation for someone to do something or conveys someone else's instructions.

Examples:
Kinder zum Hotelier: Der Pinguin soll bleiben.
= The children request that the penguin be permitted to stay.
Krankenschwester zu Harry: Sie sollen zum Doktor gehen.
= The nurse relays to Harry that the doctor would like to see him now.
 

"wollen" means to want to do something. It is used to express a strong wish, desire or intention to do something.

Examples:
Ich will jetzt frühstücken.
= I am hungry and want to eat now.
Wir wollen heiraten.
= We intend to be married. / We want to get married.

"möchten" means someone would like to do something. Like "wollen", it signifies the wish to do something, but it is more polite.

Examples:
Harry möchte in die Stadt fahren.
= Harry would like to go to the city.
Was möchten Sie (haben)?
= The waitress politely asks Harry what he would like to order.