Student or Learner
I'm trying to learn when to use the preposition of in,on,be, and at. I would like if anyone could help me to understand these concepts.
"in, on, at" are prepositions. Look here: Prepositions of Location: At, In, On
"to be" is a verb, often used as an auxiliary verb = http://www.usingenglish.com/glossary...iary-verb.html