Most Common Compounds Set 1:
Most Common Compounds Set 2 :
| Beginner - Low Intermediate: 2170 (verb: to go back and forth / round trip)  He already booked a round-trip ticket to London.  Er hatte bereits ein Hin- und Rückflugticket nach London gebucht.  Anh ấy đã đặt vé khứ hồi tới London. |