cái điều đầu tiên 
the first thing [ 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)
[ điều ] : (1) thing, matter, item; article (of penal code, constitution); (2) smoking pipe; (3) bird [=chim]
[ đầu ] : (1) beginning, first; (2) head, mind, pole, end, hood (of a car)
[ tiên ] : (1) fairy, spirit, immortal being; (2) first; (3) whip; writing paper
Most Common Compounds Set 1:
Most Common Compounds Set 2 :