The modal particle 啦
A modal particle (语气词) is a function word that adds additional semantic meanings to the sentence or emotionally colors it. It is usually placed at the end of a sentence.
The particle 啦 
has several functions. Let's consider each of them:
1) expresses joy, admiration, surprise or anger.
has several functions. Let's consider each of them:
1) expresses joy, admiration, surprise or anger.Examples
我们完成任务啦！
We have completed the task!
wǒmen wánchéng rènwù la
看看他，他失掉良心啦！
Look at him, he has lost his conscience!
kànkan tā, tā shīdiào liángxīn la
2) expresses satisfaction.
Examples
好啦，我可以跟你一起去逛街
Okay, I will go shopping with you
hǎo la, wǒ kěyǐ gēn nǐ yìqǐ qù guàngjiē
行啦行啦，不用说那么多的话
Alright, alright, no need to say so much.
xíng la xíng la, búyòng shuō nàme duō de huà
3) used when clarifying or explaining.
Examples
你都听明白啦？
You got it, didn't you?
nǐ dōu tīng míngbai la
有错, 改了就行啦
There is a mistake. Just change it and it’ll be okay
yǒu cuò, gǎi le jiùxíng la
4) is used when listing nouns to emphasize them or to fill the pause between them.
Examples
我厌烦数学 —— 尽是些等式啦核算啦什么的
I'm sick of maths — all those equations, calculations and other stuff
wǒ yànfán shùxué — jìn shì xiē děng shì la hésuàn la shénme de
花啦、礼物啦，都预备好了！
The flowers and gifts are all prepared well!
huā la, lǐwù la, dōu yùbèi hǎo le
You can also use 啦 instead of 了
1) as a suffix after a verb, to indicate the completion of an action.
1) as a suffix after a verb, to indicate the completion of an action.Examples
我们已经输啦，没必要伤心
We've lost, but there is no need to be sad
wǒmen yǐjing shū la, méi bìyào shāngxīn
这个电脑坏啦
This computer is broken
zhè ge diànnǎo huài la
2) As a modal particle at the end of a sentence to indicate a change in a situation.
Examples
你不理我啦？
Are you ignoring me now?
nǐ bù lǐ wǒ la
你来啦！
You came!
nǐ lái la
大楼终于建成啦！
This building has finally been constructed!
dàlóu zhōngyú jiànchéng la