Common Mistakes : Continual

adjective

.BAD: The canals join to form one continual waterway
.GOOD: The canals join to form one continuous waterway

.BAD: A line of cars stretched continually down the motorway
.GOOD: A line of cars stretched continuously down the motorway

continual = happening repeatedly over a long period of time, especially in a way that you find annoying
.That telephone has been ringing continually

: continuous = without any break or interruption
.Gas central heating provides a continuous supply of hot water