hmm... for ke lian is more to the mandirin side.. hor lin and chai leong is no diffrent the meaning.. both also pitiful. it really depends on the situation..  such example can be lyk for chai leong.

u working 24 hhours a day and ur grand ma say... songg chai leong looooooo

hor lin is more lyk i pity u . its lyk a begger on the ground.. soog hor lin

saopei

ke lian = mandarin

hor lin = pitiful

chai leong = sadful

mo ku = innocent

hor lin (  pity )
chai leong ( sadful )
kelian <--- is mandarin

mo ku <-- yuen wong <-- innocent

What "pek cek" means? As in "Hou pek cek aaah" 

Lau Yat mm'si lang kii eh!!

mok teik = intention
yin yan = what is this?

what would be the right scenario to use for each? i've put common scenarios i've heard these phrases being used:

chai leong = baby crying non-stop
hor lin = an old lady who has to work hard to make a living
mo ku = a guys who gets blamed for something he didn't do

does that work? or can 3 words be used interchangeably?

What "pek cek" means? As in "Hou pek cek aaah" 

ke lian is mandarin, same as ho lin in cantonese which mean pitiful.
When a dog was neglected by its owner, we say "That chiwawa is so "ho lin".

chai leong means very pitiful until you feel like crying.
Like when you see someone got bullied and abused to the extreme then you feel the pain and feel like crying, you use "chai leong".

It's not "mo ku", "mo ku" is those canned mushroom you see in supermarket. It's "mou ku" which means innocent.
When someone accused you for stealing, you shout out loud "I'm "mou ku", I'm innocent I did not steal or you can say "I'm yuen wong" which means you are being wrongfully accused for something that you did not do. 

female colleague?

means "datang bulan" 

ngor hor lin nei 5 sek gong dong wa, chai leong lo nei hai 5 hai tong yan lai gah? yu gor hai ga wa shang gao cha siu hou gor shang nei ....

heng chuk = celebrate

Lei yeh - A statement describing someone menstruating (literal meaning). This is used colloquially. (a different tone of the same pronunciation can also mean, got into deep shit, or an exclamation of shit has just hit the fan).

A more polite term is 'lei keng khei'. (for menstruation)

In slang term for menstruation, usually people will use 'tai yee ma' (literal translation - big aunty, makcik sulung). Example of usage:

"She is having her tai yee ma". "Her tai yee ma is visiting".

Also could be used to describe someone who is being too difficult.

"What is wrong with her?? Having a taiyeema??"

It's really difficult learning Mandarin or Cantonese in words, because of the tones. Different tones will bring different meaning altogether.

then u shld not bad in gong dong wa....

Hor Lin - pitiful or sympathize - depending on usage. To be used as adjective and transitive verb. eg: I can hor lin someone, and lend him a helping hand. Someone's plight can be very hor lin, and beckons for a lot of sympathy.

Chai Leong - A state of absolute sadness, dejection, bereavement, despair, sorrow (you get the idea). This is purely an adjective. Eg: A person shedding tears watching a chai leong movie. Or a state of a kid crying in a chai leong manner.

Both phrase have only slight difference when used as adjectives, otherwise, they're completely different.

Mou Ku - innocent. Pretty straight forward. Adjective only.

should be 'sang' (like sang kancil). Means, to give birth to, or grow (for objects/growth/skin disease).

the phrase you should really learn --> *** nia seng.

 

Actually, 'chow wa' isn't really a correct term in Cantonese to describe 'profanity'. That phrase is localized direct translation from Hokkien. The correct term should be 'Chou hau'. (literally, translates to 'impolite mouth').

Eg:
kong chou hau. (Speaks profanity)

Mm hou kong chou hau. (Do not use profanities, or mind your language).

Hok kong chou hau, lor sam yat. (Takes 3 days to learn profanities).
Hok hou yeh, lor yat sai (Takes a lifetime to learn the good stuffs).

I wouldn't use 'yiu / yew' (the meaning's more towards 'want' rather than 'need/require'). Makes you sound like a horny pornstar. LOL.

'Lor' is a better substitute, since it will make it sound like 'will take'.

eg:
Lor see kan (takes time).