Hi

I think that the pronounciation is the most important part when you speak Cantonese..hmm you dont have to know how to write it..but you better make sure you are pronouncing it correctly.

just like mandarin, the meaning of the word will be different if the tone(i mean shengdiao) is different..esp there are more tones in cantonese..wish you good luck anyway

i was born in guangzhou and thats just my personal suggestion as a native who will hear from foreigners.i hope my answer will help you^^