e.g. Do you often watch television?

Often is an adverb of frequency. You should put the frequency verb before an ordinary verb, after the verb be and the auxiliary.

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Is my explanation about the use of 'often' grammatical? Would you let me know whether there are any errors?
Do I have to use a frequency adverb or an adverb of frequency?

1 answer

Your explanation is good. And the phrase "frequency adverb" is fine; the phrasing "adverb of frequency" is correct also, but a bit stuffy!

=)