The adverbs continuously and continually (and their corresponding adjectives, continuous and continual) are words that are confused easily and often. Continuously describes an action that happens without ceasing. Continually, on the other hand, describes an action that recurs frequently or regularly.
The confusion about whether to use continually or continuously is understandable, because both words share the same Latin root, continuare, meaning “to join together or connect.” Only the endings of the words are different, and over time, the two words have evolved with subtly distinct meanings.