了

了

to finish
(used with 得 dé or 不 bù after a verb to express (im)possibility, as in 忘不了 wàng bu liǎo "cannot forget")
(literary) (usually followed by a negative such as 无 wú or 不 bù) completely (not); entirely (not); (not) in the least
to understand clearly (variant of 了 [瞭] liǎo)

了

(completed action marker)
(modal particle indicating change of state, situation now)
(modal particle intensifying preceding clause)

Example sentences

这件衣服太贵了。
zhè jiàn yīfu tài guìle.
This piece of clothing is too expensive
我工作一天了，现在我只想睡觉放松。
wǒ gōngzuò yītiān le, xiànzài wǒ zhǐ xiǎng shuìjiào fàngsōng.
I have worked for a whole day long, now I only want to sleep and relax

了 [瞭]

(of eyes) bright
clear-sighted
to understand clearly

了 [瞭]

unofficial variant of 瞭 liào