Although it is grammatically correct to respond to the question How often? with sometimes, you still haven't answered the question. When asked how often, try to give more information - no matter how infrequently you do something.
After 'How often' try to respond with a number + times + and a period:
Adverbs of frequency - sometimes, always, seldom, etc - are more common in response to the question do/are you ever?
But even in these situations it's a good idea to give additional information. Why only sometimes? Why rarely? etc.
In the box below, try and complete the question from this post's featured image. Then click for possible questions!