Under the conditions given, "to" is a preposition.
Yes, a proper noun is a type of noun that specifically names a unique person, place, thing, or idea and is typically capitalized. It is part of the broader category of nouns in the classification of parts of speech in grammar.
The word "core" can function as a noun, adjective, or verb. It is most commonly used as a noun to refer to the central or most essential part of something.
The part of speech for "archaeologist" is a noun.
Ethics code is a noun. It is rules of code which must be followed in order to be ethically correct.
Permission is a noun.
The part of speech for "touchdown" is a noun.
Ethics code is a noun. It is rules of code which must be followed in order to be ethically correct.
The part of speech for the word diplomacy is a noun.
The word speech is a noun.
A noun, specifically a proper noun.
Noun
There is only one part of speech in a noun--noun.