Adverbs can be categorized into groups including time, frequency, manner, and purpose. Adverbs of time include early, late, before, after, next. Adverbs of frequency contain every day, always, seldom, frequently, never. Adverbs of manner are slowly, fast, quietly, loudly, quickly. Adverbs of purpose involve to get good marks, to avoid falling, to hit the target, to avoid the rocks, to get the best results.