Answer:
1.)rarely
2.)sometimes
3.)always
4.)periodically
Explanation:
An adverb of frequency describes how often an action happens. There are six main adverbs of frequency that we use in English: always, usually (or normally), often, sometimes, rarely, and never. ... A good way to explain the difference in frequency is by using %.
Adverbs of frequency include; always, constantly, continually, frequently, infrequently, intermittently, normally, occasionally, often, periodically, rarely, regularly, seldom, sometimes etc.
