If this question is a mathematical one than the answer is 3d - 25
Yeah, where are the sentences. I can help, I just need to see them.
Answer: "am" is never a "preposition". Rather, "am" is a "first-person, present tense, singular" conjugated form of the verb, "to be" (in English); that takes the subject pronoun, "I".
"am" is a "verb"— and never a preposition.
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Are dolphins smarter than humans? Trust me, it seems simple, but I once did a research paper on it and I ended up writing a poop ton of stuff.
Hope this helps! Have a great day :)