Hello,
I have gone through grammar books and online sites. Most of the online sites and some grammar books show that there are 5 types of adverbs. There are
adverb of manner - place - time - frequency - degree.
So, what about adverb of purpose/reason and adverb of cause/effect?
Are these types belong any other category?Please help me with this question.
Five isn't a magic number. You could purpose and causal to that list. (They would probably come under "manner" in a 5-term ontology of adverbs).
The important thing is to recognise them as adverbs, and identify why there are there. Grammar lists like this should be a tool to help you, not a constriction on your understanding.