Both adjectival forms, continual and continuous,
mean without stopping or without a break. They are
often used interchangeably:
- This refectory has been in continual /continuous use
since the 15th Century.
- The continual / continuous croaking of the frogs prevented
any sleep that night.
In certain contexts only continuous is possible because
continual here would imply that breaks are possible. In these
examples, there are clearly no breaks, so continuous is preferred:
- A continuous line of people stretched as far
as the eye could see.
- They executed the dance in one continuous movement.
- The progress of pupils was measured though continuous
assessment and not through examinations
When we want to describe things that happen repeatedly, continual
- His continual drinking was bound to lead to liver
failure one day.
- He refused to give up despite the continual warnings of
continually - continuously
The adverbial forms, continually and continuously,
are often interchangeable.
- She sniffed continually / continuously all the way
through the film and disturbed everyone around her.
But when the meaning is clearly very often, rather than
without a break, continually is preferred:
- I've got a very bad stomach upset and I'm continually
running to the loo.
Here, continually is behaving as an adverb of frequency,
cf. always, all the time, constantly. If we arranged
such adverbs along a continuum of frequency, starting with least
often and ending with most often, it would read:
- never > rarely > occasionally > sometimes > often
>generally > nearly always > constantly/continually