'all bark and no bite'; all talk and no action; 'all mouth and no trousers'
Definitions (粵典–words.hk)
語句
齋講或者應承做一件事,但係冇實際嘅行動 used to describe someone who is only good in talking but does nothing to support what he or she says; to pay lip service to; to have a plan which will never be put into effect
「下次我請大家食飯嘞。」「你得個講字嘅!你講咗好多次啦,都冇次係真嘅。」
「下次我请大家食饭嘞。」「你得个讲字嘅!你讲咗好多次啦,都冇次系真嘅。」
haa6 ci3 ngo5 ceng2 daai6 gaa1 sik6 faan6 laak3. nei5 dak1 go3 gong2 zi6 ge2! nei5 gong2 zo2 hou2 do1 ci3 laa1, dou1 mou5 ci3 hai6 zan1 ge3. "I will buy everyone dinner the next time." "You said it several times before. You never keep your words."