"yopwaHwIj tuQtaH qoqvetlh!"
Translation:That robot is wearing my pants!
The Klingon word yopwaH only and always refers to trousers. In the US those are also called "pants" and Duolingo asks contributors to use American English. However, "trousers" is an accepted translation of the word. We do not know of a Klingon word for underpants (or if Klingons even wear them).