了 le liǎo

Action marker to indicate that an action has already been made

• 说了 (shuō le) Said or has/have/had said Literal. Say already
• 喝了酒 (hē le jiú) Drank or has/have/had drunk wine Literal. Drink already wine
• 吃了榴莲 (chī le liú lián) Ate or has/have/had eaten durian Literal. Eat already durian

• 了解 (liǎo jiě) Find out / Understand Literal. Understand and explain
• 明了 (míng liǎo) Fathom Literal. Clear and understood
• 了如指掌 (liǎo rú zhǐ zhǎng) At one's fingertips Literal. Understood as good as fingers on palm
• 一目了然 (yī mù liǎo rán) Very clear / Obvious Literal. One glance understood this

• 了结 (liǎo jié) Conclude Literal. Ending a knot
• 不了了之 (bù liǎo liǎo zhī) Unsettled / No outcome Literal. No (proper) ending, (but) end at that
• 没完没了 (méi wán méi liǎo) Never ending Literal. Without completion, without end
• 一了百了 (yī liǎo bǎi liǎo) Once the main problem is solved, all problems cease to exist Literal. One end, hundred end – in the past, it was widely used to mean "death ends all problems". In modern context, it is often used to mean "settle it once and for all" especially when ending a relationship.