There are five types of adverbs in the English language. Adverbs of frequency express how often an action takes place. The most common frequency adverbs are always, never, rarely, and usually.
Rule 1: Adverbs of indefinite frequency should be placed directly before the main verb but after the auxiliary verb.
She usually wakes up at 7 am.
Usually is an adverb if indefinite frequency, so in the sentence it is placed before the main verb wakes up.
He has never played guitar before.
Never is an adverb of indefinite frequency, so in this sentence it is placed after the auxiliary verb has and before the main verb played.
The only exception is the verb be. In such a case, a frequency adverb comes after.
She is rarely at the gym.
Is is a form of the verb be, so the adverb of indefinite frequency rarely is placed after.
Rule 2: The adverbs usually, normally, often, frequently, sometimes, and occasionally can be placed at the beginning or the end of the sentence. Their placement affects the emphasis of the sentence.
I have a cup of coffee in the morning usually.
Usually is an adverb of frequency used, in such case, to describe the normal state of things.
Sometimes, I decide to have a cup of green tea instead.
Sometimes is a frequency adverb used, in this case, to describe an exception.
Rule 3: Adverbs of definite frequency should be placed at the end of the sentence but can also go at the beginning of it. These include today, daily, tomorrow, every week, etc.
I go to sleep at 10 pm daily. / Daily, I practice yoga.
Daily is an adverb of definite frequency that describes an action that repeats day-to-day.
Place the adverb never in the sentence: She has driven a car.