Some words are added to a sentence to say how often something is done:

always
usually
sometimes
rarely
never

always = 100%
usually = >50%
sometimes = <50% rarely = a small number of times never = 0% - examples I always brush my teeth before I go to bed. (= 100%)
I usually read before I go to sleep. (>50%)
I sometimes watch a DVD on my computer in bed. (<50%) I rarely go to bed before 11pm. (a small number of times)
I never eat after I brush my teeth at night. (0%)

Exercise

Describe your week using the frequency words ‘always’, ‘usually’, ‘sometimes’, ‘rarely’, and ‘never’.