What is an adverb ?

What is an adverb ? How many types and what are they ?
উত্তরঃ Adverbs are words that are used to give additional information about a verb, adjective or adverb in a sentence or to make the given information more meaningful. একটি বাক্যে Verb, Adjective বা Adverb (সম্পর্কে অতিরিক্ত তথ্য দেওয়া বা প্রদত্ত তথ্যকে আরো তাৎপর্যতাপূর্ণ করে তুলতে যে সকল word ব্যবহার করা হয় তাঁকে adverb বলে )
একটি বাক্যে কখন? /কোথায়? / কিভাবে? / কি উপায়ে? এবং কি পরিমাণে? এগুলো দিয়ে প্রশ্ন করে যে উত্তর পাওয়া যায় সেটি adverb
He works extremely hard.
The leopard runs quickly
Most of our countrymen are very poor.
Kinds of Adverbs: 
i. Adverb of Time: Indicates the time of an action, and answer the question ‘when’?
Such as now, soon, still, then, today, yet, since, back, ago, already, before, after, recently, today, lately, tomorrow, once, someday, early, etc.

ii. Adverb of Manner: Expresses the manner of an action, and answer the question ‘How’?
Such as happily, slowly, quickly, carefully, loudly, easily, fast, bravely, hard, well, badly, etc.

iii. Adverb of Place: Indicates the place of an action, and answer the question ‘Where’?
Such as here, there, up, down, in, out, by, hither, thither, where, anywhere, somewhere, everywhere, nowhere, etc.
iv. Adverb of Degree or Quantity: Expresses quantity, and answer the question ‘How much/ How far/ to what extent’?
Such as extremely, fully, quite, almost, very much, too, a lot, totally, absolutely, fairly, hardly, etc.
v. Adverb of Affirmation and negation: Indicate assertion and express the one’s reaction to question.
Such as yes, no, yeah.

vi. Adverb of Frequency: Expresses the frequency of an action and answer the question “How often”?
Such as never, ever, always, often, seldom, everyday, sometimes, usually, normally, frequently, rarely, hardly, scarcely, once a week, etc.

vii. Adverb of reason: Expresses the reason and make the conclusion.
Such as hence, therefore, thence etc.

Conjunctive Adverb:
as also, finally, furthermore, consequently, hence, however, incidentally, indeed, instead, likewise, nevertheless, meanwhile, next, nonetheless, otherwise, then, still, thus, and therefore.

Position of Adverb: i. Adverbs of time usually come at the end of a sentence or at the beginning of sentence. ii. Adverbs of place usually follow the verb. iii.    Adverbs of Degree or Quantity come before the verb, adjective or adverb.