Longman Dictionary of Contemporary English - continual

~ adj 1 continuing for a long time without stopping  (five weeks of continual rain | The hostages lived in continual fear of violent death.) 2 repeated often and over a long period of time; frequent  (The continual trips to my mother's house took up a lot of my time.) 3 used to describe actions that are repeated many times over a period of time and are annoying  (I wish you'd stop that continual chattering!) - continually adv  (continually reassessing the situation)  ( USAGE NOTE: CONTINUAL WORD CHOICE continual (ly), continuous (ly) Continual describes separate actions (often annoying actions you do not like) which are repeated over a period of time These continual interruptions are driving me mad. | She's continually flying off to different places. Continuous especially describes things and events that go on without a break The police formed a continuous line round the building. | This product is the result of years of continuous development. | We landed after flying continuously for 16 hours. The uses just described are regarded by many as the correct ones, but native speakers often use continuous (ly) also, like continual (ly), to describe repeated separate actions There were continuous interruptions. As a result, continuous (ly) is much more frequent in spoken English. Where both might be used, continuous (ly) may carry less of the idea that the repeated action is annoying It rained continuously all summer, which was good for the rice crop. Compare It rained continually all summer, which completely spoiled our vacation. )