光說不練

all talk and no action (idiom) / to preach what one does not practice / same as 光說不做|光说不做[guang1 shuo1 bu4 zuo4]

light / ray / CL:道[dao4] / bright / only / merely / to use up

to persuade

to speak / to say / to explain / to scold / to tell off / a theory (typically the last character in a compound, as in 日心說|日心说 heliocentric theory)

to speak; to talk; to say / to explain; to comment / to scold; to tell off / (bound form) theory; doctrine

no; not so / (bound form) not; un-

to practice / to train / to drill / to perfect (one's skill) / exercise / (literary) white silk / to boil and scour raw silk