Adverbs most often modify verbs and adjectives, but can modify prepositional phrases, other adverbs, and whole clauses.
One can run (run is the verb), or one can run quickly (run is the verb, quickly the adverb).
You can have an egg (noun), a cooked egg (egg is the noun, cooked the adjective), or a well cooked egg (egg is the noun, cooked is the adjective describing what type of egg, and well is an adverb describing how it is cooked).
Adverbs often answer the questions how?, when? or where?
Three main categories of adverbs, or adverbial phrases (a collection of words that acts as an adverb) are those of time, manner, and place (when, how, where), and in German they occur in a sentence in the order (1) time, (2) manner, and then (3) place.
|Jeden Tag||lese ich||langsam||die Zeitung||zu Hause .|
Another area where German syntax may vary from that of English is the position of expressions of time (when?), manner (how?) and place (where?). In English we would say:
|Erik||is coming||home||on the train||today .|
English word order in such cases is place, manner, time... the exact opposite of German.
In English it would sound odd to say
|Erik||is coming||today||on the train||home .|
, but that is precisely how German wants it said:
|Erik||kommt||heute||mit der Bahn||nach Hause .|
The only exception would be if you want to start the sentence with one of these elements for emphasis.
|Heute||kommt||Erik||mit der Bahn||nach Hause .|
(emphasis on today).
But even in this case, the elements are still in the prescribed order: time (heute), manner (mit der Bahn), place (nach Hause). If we start with a different element, the elements that follow remain in their usual order, as in:
|Mit der Bahn||kommt||Erik||heute||nach Hause .|
Mit der Bahn kommt Erik heute nach Hause. (emphasis on by train - not by car or plane)