談兵 [谈－]

Jyutping taam4 bing1
Pinyin tán bīng

Definitions (Wiktionary)
  1. verb, literary
    to discuss military tactics
Examples (粵典–words.hk)
  1. Cantonese
    佢净系识纸上谈兵，我从未见过佢亲自落场！
    佢淨係識紙上談兵，我從未見過佢親自落場！
    • He only knows how to theorizing, I have never seen him in the field.