了

to finish; (used with 得[de2] or 不[bu4] after a verb to express (im)possibility, as in 忘不了[wang4 bu5 liao3] "cannot forget"); (literary) (usually followed by a negative such as 無|无[wu2] or 不[bu4]) completely (not); entirely (not); (not) in the least; to understand clearly (variant of 瞭|了[liao3])