The word proven is an adjective. It descrbes something that has been proved.
part of speech
Adjective
What part of speech is thaw
The part of speech for oscillate is verb.
An adjective is a part of speech.
"cried" is the past tense form of the verb "cry". To prove it is a verb, you can use it with a subject: "I cried, you cried, they cried".
I don't know if you asking about a part (a portion) of a speech; or are you asking about the parts of speech in grammar (like nouns, verbs, adjectives). If you are asking about the parts of a speech, these would be the Introduction (in which you give your main theme or your thesis statement-- what you plan to prove); the body of the speech (in which you provide proof or evidence, build your case, and prove your point); and the conclusion (in which you sum up your paper and end on a positive note, if possible). As for how you write a part of speech, they are just words: for example, a "noun" refers to a person, a place, or a thing. Some examples: teacher, book, dog, zoo, Massachusetts, Spain, shoes, cupcakes.
part of speech
The part of speech for this particular word is a noun.
The part of speech for "answer" is a noun.
adverb
what part of speech is beneath
The part of speech for "explicit" is an adjective.
The part of speech for "twirl" is a verb.
The part of speech for "unfamiliar" is an adjective.
The part of speech of "came" is a verb.
The part of speech for "lecturer" is a noun.