How to differentiate between 'adverb of manner' and 'sentence adverb' as both ends with 'ly'?
Adverbs of manner describe a verb. For example: He left the room quickly.('quickly' describes the verb 'left')
It is usually placed after the verb or the object. It can be a word that does not end in '-ly'. For example: She runs fast.
A sentence adverb qualifies a complete sentence. For example: Clearly, education is more than mugging up facts or gaining some knowledge.
It is usually placed at the beginning of a sentence.