Adverbs of frequency normally occur:
-After the verb be: They are rarely late for school.
-Before the main verb: They usually start work at eight.
We sometimes misinterpret the data.
-Between the 1st auxiliary and verb: They can always work overtime.
I will often have lunch at 1 o'clock.
-Between the 1st and 2nd auxiliary: They have often been docked for being late.
You should never have said that to the boss.