了 le

我吃饭了。(completion)

Wǒ chīfànle

I ate

她的爸爸去中国了

Tā de bàba qù zhōngguóle

His father went to China

我明白了

Wǒ míngbáile

I understood

我饿了 。(Change of State, meaning he wasn't hungry earlier)

Wǒ è le.

I'm hungry

他们已经走了。

Tāmen yǐjīng zǒu le.

They already left

妈妈已经回来了。

Māma yǐjīng huílái le.

Mom is already back

宝宝会说话了。

Bǎobao huì shuōhuà le.

The baby can speak now.

你有女朋友了 ?(signaling that he didn't have before)

Nǐ yǒu nǚpéngyou le?

You already have a girlfriend?

我不想吃了 。(not anymore)

Wǒ bù xiǎng chī le.

I don't want to eat anymore

你不喜欢我了吗? (not anymore)

Nǐ bù xǐhuan wǒ le ma?

The baby can speak now.

我已经不住这里了 。(already not)

Wǒ bù xiǎng chī le.

He doesn't live here anymore

手机没电了 。(no more)

Wǒ bù xiǎng chī le.

There is no more battery in the phone

我们都去了 。

Wǒmen dōu qù le.

They all went