"She wears a pair of trousers."
Translation:Caitheann sí bríste.
Heaving a pair of trousers leads into a trap, translation only accepts bríste and doesn't accept péire bríste
This has more to do with English than Irish. In English, a pair of trousers is one thing, and this semantic object is encompassed by bríste in Irish. péire bríste would literally mean a 'pair' (i.e. two) trousers.