(Gan ga tobeba ishigame mo jidanda;
“When the goose flies, the turtle stamps”)
To try to mimic someone else without any understanding of one’s own limitations. Like a turtle who sees a goose taking off in flight, tries to fly as well, discovers that it can’t, and stamps its feet in childish frustration. The original usage seems to have a nuance of classist contempt for those who try and fail to act above “their station” in society. But, especially given the metaphor at work, it can easily be used in a more meritocratic critique.
We begin with the noun 雁 (gan), “wild goose,” marked by the particle が (ga) as the subject (doer) of the verb 飛ぶ (tobu), which appears in perfective form and is followed by the conditional suffix ば (ba). This clause is followed by another noun, 石亀 (ishigame), literally “stone turtle” but known in English as the Japanese pond turtle. This is marked by the particle も (mo) in its role as “also.” (The turtle is also grammatically a subject, but も overrides and replaces が.) And we end with another noun, 地団太 (jidanda), “foot-stamping.” This noun might normally be followed by the direct-object marker を (wo) and verb 踏む (fumu), “to step,” but these are elided.
The saying may be contracted further to just the noun phrase 石亀の地団駄 (ishigame no jidanda). If you use this version, don’t forget the shift from も to possessive の. Some people may replace 駄 with homophone 太 without any change in meaning, although this is less common.
There are quite a few roughly synonymous sayings featuring various animal pairings – the goose and doves, frogs and the turtles, carp and loaches, etc.
This saying seems to be derived from a passage in the 『東海道名所記』 (Toukaidou meishoki), “A record of famous places on the Tōkaidō road,” a mid-17th-century CE kanazōshi.
(PS. Look up the etymology of 地団駄 some time; it’s fascinating.)
(“Tashika, kodomo ga oya no mane wo shiyou to suru no wa aru shu no ishigame no jidanda da kedo, benkyou ni mo naru kara iin ja nai?”)
[“Well, kids trying to copy their parents is probably some kind of failure to recognize their own limits, but it’s fine right? It’s a learning experience.”]