The school considers him to be a problem student. (Here, problem is an adjective describing student.) Do you know how to solve the third math problem? (problem = a noun)
Each is a pronoun.
part of speech
Adjective
What part of speech is thaw
The part of speech for oscillate is verb.
Problems is a noun, the plural form of problem.
it is an infinitive phrase.
The word situation is a noun. A situation is a problem or circumstances that pose a problem.
"Complex", in this sentence, is used as an adjective. It describes the problem, a noun.
A problem is a thing, which places it in the Noun category.
Each is a pronoun.
part of speech
The part of speech for this particular word is a noun.
adverb
what part of speech is work
what part of speech is beneath
the part of speech sashay is a averb