couch : 指供昼夜坐卧，似床一样的长沙发或睡椅。
- Roy swung his legs carefully off the couch and sat up.
- She slipped out of the jacket and tossed it on the couch.
- We were sitting on the couch in the living room watching TV.
- Nicola slowly draped herself across the couch.
- He was lying prone on the couch, fast asleep.
sofa : 指有扶手和靠背，可供多人坐或一个人睡的长沙发，也泛指沙发。
- She sat down next to him on the sofa.
- The kitten was curled on a cushion on the sofa.
- I decided to ditch the sofa bed.