Prepositions are words or word groups which begin a noun phrase with more than one word. Most prepositions tell where or when, or show possession. Prepositions like in, beside, above, and out of all tell where, and are usually used with nouns or pronouns. Some examples "The man sat close to his wife. He put his arm around her shoulder. Then he kissed her on the cheek." Prepositions like right after, until, during, and before , all tell when. "Mr. Smith had an important meeting until ten o'clock. During the meeting, his cell phone rang. It was his wife. She asked him to come straight home right after work." The prepositions of and to are used to show possession, or belonging-to: "This book belongs to Omar. The cover of the book is torn."

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I do. :P

Every native English speaker knows about prepositions.