Here are some examples:
* Noun: "The foundation of a house is important." (The word "foundation" refers to the base of the house, which is a thing.)
* Verb: "We need to foundation our company on strong values." (Here, "foundation" means to establish or build upon something, an action.)
* Adjective: "That was a foundation course in biology." (Here, "foundation" describes the course as being basic or introductory.)
So, the part of speech of "foundation" will depend on its function in a sentence.