Unit 78 - Prepositional phrases TRI ĐỨC ENGLISH 2026 • Pre-Intermediate UNIT 78 PREPOSITIONAL PHRASES LÝ THUYẾT A. By, on or in + noun By by mistake I thought it was my pen. by hand not using a machine. by chance it wasn't planned; it was luck. by accident he did not want or plan to do it. On on purpose he wanted to do it; intention. on the phone using the phone. on strike refuse to work (pay, hours issues). on display in the window for people to look at. on fire burning. on board on the train, boat, plane, etc. In in a hurry needing to do something quickly....