Roxanne very happily accepted the ten-point late penalty to work on her research essay one more day.
The adverb very fine-tunes the adverb happily.
Surprisingly, the restroom stalls had toilet paper.
The adverb surprisingly modifies the entire main clause that follows.
Many single-word adverbs end in ly. In the examples above, you saw peacefully, rudely, completely, happily, and surprisingly.