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.
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.