The phrase "secondary source" is a singular noun. The plural term is secondary sources.
Reliable is an adjective, and source is a noun.
A dictionary.
The word "cite" is a verb. It is used to refer to quoting or referencing a source of information in written work or speech.
A dictionary or an online thesaurus would be a good reference source to find the part of speech for the word "really." It is an adverb that is used to modify adjectives or other adverbs in a sentence.
The part of speech for this particular word is a noun.
part of speech
The part of speech for "answer" is a noun.
adverb
what part of speech is beneath
The part of speech for "unfamiliar" is an adjective.
The part of speech of "came" is a verb.
The part of speech for "twirl" is a verb.