Final Particles: How do you use 啦, 嘞, 嚹, and 喇?
I've seen that 啦 is the most common among the above mentioned, but the ''laa'' that I've heard is not in the same tone as 啦, which sounds more like a command, a bit rude somehow... (e.g. 出來啦！get out! )
The one I've heard is really soft, something like: 我做咗功課laa (I did my homework) or 佢瞓咗laa (he/she has already slept).
What final particle could be the one I've heard? -- this is a hard question in my opinion 'cause Cantonese have many tones...

And I don't know where to find an Online Cantonese dictionary with pronunciation (audio) :/ Do you know any?
By the way, it would be great if you could compare the Cantonese final particles with other ''Mandarin'' final particles (maybe 了or 吧, if it can be compared)

Question

Final Particles: How do you use 啦, 嘞, 嚹, and  喇?
I've seen that 啦 is the most common among the above mentioned, but the ''laa'' that I've heard is not in the same tone as 啦, which sounds more like a command, a bit rude somehow... (e.g. 出來啦！get out! )
The one I've heard is really soft, something like: 我做咗功課laa (I did my homework) or 佢瞓咗laa (he/she has already slept).
What final particle could be the one I've heard? -- this is a hard question in my opinion 'cause Cantonese have many tones...

And I don't know where to find an Online Cantonese dictionary with pronunciation (audio) :/ Do you know any? 
By the way, it would be great if you could compare the Cantonese final particles with other ''Mandarin'' final particles (maybe 了or  吧, if it can be compared)

Answer

It's written as the same "啦“.
But the tone is different. I don't think it can compare with Mandarin.
laa1 used as a command.
laa3 used as a description.
These is a online dictionary that you can check the pronunciation.
http://humanum.arts.cuhk.edu.hk/Lexis/lexi-can/

Answer

If you can read Chinese, I recommend you purchasing a dictionary, since I also didn't any excellent online ones.
laa1 啦 sometimes used in invitation in a friendly way, for example 出来啦 means "please come out".
laa3 is lower than laa1, and it is often used in sigh or amazement, like 我做咗功課laa3 means "I finally finish my homework" "I have already finish my homework!"
laa4 is used in questions 你做咗功課laa4 means "You have finished your homework?"

Answer

In my personal point of view, if you have probably understand Cantonese inside every word meaning, that the rest of your need to learn the tone of dialogue with the others, different scene and the tone of the time have different tone changes. If you want me to teach you Cantonese, I also want to exercise my English listening and speaking.

Answer

Final particles are always scholars' favourite research topic so it should be easy to find resources about it. If you find reading English easier, you may check Stephen Matthew and Virginia Yip's grammar book called Cantonese: A Comprehensive Grammar. If you are OK with Chinese, try 粵語語法講義 written by Prof Tang Sze-Wing. The Google Book's link: https://books.google.com.hk/books?id=KTarCgAAQBAJ&pg=PA372&lpg=PA372&dq=%E9%84%A7%E6%80%9D%E7%A9%8E&source=bl&ots=ujIm9Ur0y8&sig=hK4FstWd-w-rIIdONIMUaptyXu8&hl=en&sa=X&ved=0ahUKEwjlsreTjczNAhWMFZQKHU6eByEQ6AEIbzAO#v=onepage&q=%E9%84%A7%E6%80%9D%E7%A9%8E&f=false.