I went to the beach.
which has one subject, the pronoun 'I,' and one verb, 'went.'
A dependent clause also contains a subject and a verb, but it can't stand alone because it doesn't form a complete thought:
When I go to the beach
is an example of a dependent clause. It has a subject, 'I,' and a verb, 'go,' but because it begins with the word 'when,' it doesn't form a complete thought because the listener expects to hear something after 'beach.'