Prepositions Prepositions tell you how things are related to one another – their position. Where: where one thing is in relation to another thing in the sentence. (e.g. under over at on in through into) e.g. I put the book on the table. She stashed her money under her bed. He drove through the tunnel to the camp. When: when things happen in relation to each other (e.g. while during until since in before after) e.g. I fell asleep during the cricket. We study maths until lunchtime. I ate my breakfast before going to school.