Б54

НИ БЕЛЬМЕСА (НИ БУМ-БУМ) не знать, не понимать, не смыслить (в чём) highly collthese forms onlyobj (both variants) or predic with subj: human (2nd var. )) to know or understand nothing (about sth. ): X (в Y-e) не понимает ни бельмеса (X в Y-e ни бум-бум) - X doesn't know beans (squat) about YX doesn't know (understand) a thing (the first thing) about YX doesn't have the foggiest (notion) about YX doesn't have a clue about Y(of one's command of a foreign language, technical jargon etc) X doesn't know (understand) a word of Y(of a foreign language only) X can't say two words in (speak a word of) Y.