Time adverbs indicate when something happens or how often something happens. They can express a point in time, a frequency, or a duration. In a sentence, they are often in the middle field, i.e., after the finite verb in main clauses. Time adverbs generally do not inflect for person or number.

Adverbs of frequency describe how often something happens. They usually come before the main verb or after the subject in a sentence. In combination with time expressions, the order can vary, but the meaning remains stable.

Adverbial expressions of duration indicate how long a state or action lasts. In German, this is often expressed using time expressions with 'lang' or fixed phrases. The duration can stand in the accusative without a preposition when it refers to a period as a whole.

Time adverbs of sequence order events chronologically. They often connect sentences or sentence parts and structure processes. In German, they often appear at the beginning of the sentence or in the middle, depending on emphasis.

Concrete time expressions such as times and days are often used as adverbial modifiers. In German, times of day are usually expressed with the construction with 'um', days often without a preposition. Seasons, months and weekdays can appear with or without an article, depending on the context.

Temporal prepositions join nouns with a time meaning and govern a case. 'Um' is used with times, 'am' with days and times of day, 'im' with months and seasons. 'Seit' is used with the dative and expresses a starting point that continues.

Time adverbs express point in time, frequency, duration, and order, and often appear in the middle field. Fixed prepositions such as 'um', 'am', and 'im' clearly connect time expressions to the case. With these tools you can express temporal information in German precisely.