口では大坂の城も建つ（くちではおおさかのしろもたつ）

Japanese vocabulary

Meaning: talk is cheap; it's easier to say than to do; building Osaka Castle by talking

See it used in real works

• Example sentences from Japanese novels & web fiction (Massif)
• Hear “口では大坂の城も建つ” pronounced in real videos (YouGlish)