Another tricky name for a simple idea. A fronted adverbial is an adverb or adverbial phrase that has been moved to the start of the sentence. Usually the adverb goes next to the verb but fronted adverbials can be used to create a more interesting sentence, just by rearranging the word order.
The old man stared silently into the far distance.
This can be changed to:
Silently, the old man stared into the distance.
The emphasis is now on the silence.
Note that a comma is normally used after a fronted adverbial.
We have kept this exercise very simple, concentrating on single adverbs rather than phrases. Children are usually taught about fronted adverbials in Year 4.