Although "-ly" is the general rule to derive adjectives into adverbs, there are other suffixes like "-ward", "-wise", "-fold" or "-most" that can be used when the meaning is different (indicating, direction, manner, quantity, etc.).

Some adverbs are simply not derived from nouns or adjectives and have an original form like "not", "just" or "down".

It is also possible to find compound adverbs like "flat out" or "two-handed".

See the full list below: