2meih gaai náaih 未戒奶 — yet to quit milk; young and immature.
3meih gau bāan 未夠班 — not good enough, not powerful enough.
4meih gau ching 未夠秤 — not old enough (for a job, to have sex, to work as a prostitute, etc); not senior enough (for a task, to represent an organisation).