To classify a dependent clause, you need to determine how the dependent clause relates to the independent clause. If it is replacing a noun, it is a noun clause. Try replacing it with the indefinite pronouns something or someone.
I know that you were late yesterday. (I know something.)
I bought these cards for whenever I might need some extras. (I bought these cards for something.)
If it is modifying a noun, it is an adjective clause. An adjective clause tells which one or what kind.
The birds that are singing so loudly are monk parakeets.
If it is modifying a verb, adjective, or adverb, it is an adverb clause. An adverb clause modifying a verb tells when, where, how, why, to what extent, or under what conditions. Adverb clauses can be moved around in the sentence.
Before you eat that brownie, you should read the ingredients.
You should read the ingredients before you eat that brownie.
The team was relieved that the referee's call went their way.
In the library, we worked quietly so we wouldn't disturb anyone.