Adverbs of frequency

Always, frequently, often, once, twice, sometimes, usually, ever, hardly ever, never, rarely etc.
Adverbs of frequently are normally placed before the main verb.
e.g I usually travel buy bus. He hardly ever eats meat.
However, adverbs of frequency are placed after the verb to be and after auxiliary verbs.
e.g She is sometimes late for work. Have you ever visited Disneyland?