Duǎntú lǚxíng zuò ruǎnzuò jiù gòu le, búyòng mǎi wòpù.
For a short trip a soft seat is enough; there's no need to buy a sleeper.
Tips
usage
软座 cars are now found mainly on older conventional trains. On high-speed lines the comparable seats are in first class; the standard class there is 二等座 "second-class seat".
