The main subject and verb are underlined:
Ex: Researchers reported that the Earth is warming up.
The clause in violet functions as the object of the verb reported.
The phrase Researchers reported cannot stand on its own as an independent clause. The verb reported is transitive. It needs an object.
The clause The Earth is warming up can stand on its own. It's an independent clause there, but in our example sentence it begins or is headed by the word that which makes it a dependent clause.
In short, look for small words, words that head clauses, and you'll be able to tell whether the clause functions
dependently or not. As for independent clauses, look at the verb. Is it transitive or intransitive?
Does that help?