The -ly rule confusion in identifying adverbs:
Generally we see:
He is walking slowly.
Here, slow + ly = Adverb
Some Adverbs do not follow this rule. These are irregular adverbs.
For example, some adverbs and adjectives look exactly the same. Although they look the same, it is easy to know the difference because adjectives describe nouns while adverbs describe verbs, adjectives, or adverbs.
The early bird gets the worm. (adjective)
He always arrives early. (adverb)
Those daily emails are too long. (adjective)
She writes emails daily. (adverb)