些成双成对的名词常以s结尾的复数形式出现,表示复数意思。例如:trousers长裤,pants裤子,shorts短裤,jeans牛仔裤,shoes鞋子,glasses眼镜,compasses圆规,scales天平,pliers钳子,clips剪子,headphones耳机,等等。这些名词单独作主语时,谓语用复数。例如:Your trousers are put on the bed.你的裤子放在床上。Where are my glasses?我的眼镜在哪里? These pairs of nouns often appear in the plural at the end of s, indicating plural meanings. For example: trousers trousers, pants pants, shorts shorts, jeans jeans, shoes shoes, glasses glasses, compasses compasses, scales scales, pliers pliers, clips scissors, headphones earphones, and so on. When these nouns are used as the sole subject, predicates are plural. For example: Your trousers are put on the bed. Your pants are on the bed. Where are my glasses? Where are my glasses?