There are two possibilities, depending on what exactly you mean: 你说普通话还是广东话？ 你说普通话或者广东话吗？ These can both be translated as "Do you speak Mandarin or Cantonese?", but they're slightly different. "你说普通话还是广东话？" -This means "Do you speak Mandarin or do you speak Cantonese?". People would respond with either "Mandarin" or "Cantonese". '还是‘ is a question word, and makes the sentence a question in which the response must be one of the two options. "你说普通话或者广东话吗？“ -This means "Do speak at least one of Mandarin or Cantonese?". In English, we'd respond with 'yes' or 'no'. In Chinese, they'd say ‘说’ or ‘不说'. ‘Cantonese' can be either '广东话’ or '粤语'.

Some of the characters used are incorrect. Also, you need to repeat the verb after "还是". The correct sentence would be: 你好，你说普通话还是说广东话？ and it does translate to "Hi, do you speak Mandarin or Cantonese?" HTH

You should practise your pinyin. I guess you are using pinyin input method to type hanzi. This may sound more natural. nihao. ni shuo putonghua haishi yueyu? (你好。你說普通話還是粵語？) note:Guangdonghua includes Cantonese,Hakka Chinese , Teochew and more sub dialects. (廣東話包括粵語、客家話、潮州話等多種次方言。)

You should practise your pinyin. I guess your are using pinyin input method to type hanzi. this may sound more natural. nihao. ni shuo putonghua haishi yueyu? (你好。你說普通話還是粵語？) note:Guangdonghua includes Cantonese,Hakka Chinese and Teochew and more sub dialects. (廣東話包括粵語、客家話、潮州話等多種次方言。(

My two daughters aged is near 14 and study at seven grade. They will step eight grade after the summer vacation. Would you like to exchange English and Mandarin with them two. They will get final term exam on June 27th and 28th. I hope they can improve English speaking and listening skills during the two months vacation. They speak Mandarin. Nice to meet you.