bé cái nhầm 
make a mistake [ bé ] : little, small, tiny, young (before the name of a child)
[ cái ] : (1) [CL for most inanimate objects, isolated events]; (2) object, thing; (3) female; (4) main, principle; (5) solid substances in soup (as opposed to nước, the liquid, broth)
[ nhầm ] : to make a mistake; wrong
Most Common Compounds Set 1:
Most Common Compounds Set 2 :