I think that it is surprising to see that fellow South East Asian are not aware about their fellow South East Asian and because I found that so many people seems like having difficulties to understand about anthropology and social in South East Asia mainland. I will help brothers and sisters who never mingle with Chinese people and South East Asian mainland people including my own compatriot Muslim brothers of Malay ethnicity. Just consider this as your entertainment and it is my service for brothers. Next time when you wanted to mingle with people you already have some ample knowledge about people and not asking questions which actually make people surprise and feeling sad because you are not caring about your neighboring countries.
There are few countries who were influenced by Chinese culture. The most close one is Vietnam where they were just at the tip of Southern China. Their language is known as 國語 Kwok Ngu which was written using Chinese characters and the combination of native creation of Chinese characters local to them known as 字喃 Chu Lom. The people there were known as southern Yue.
The Yue people are the people of Southern China and Cantonese language or Southern Chinese language is also called as Yue but it is spelled differently. In Mandarin Chinese usually I just refer it as 白話 bai hua. I am familiar with this dialect when I was a child and during my sisters lower education they were also educated in Cantonese as Catholic mission school operated from Hong Kong. Malaysian TV like channel 2 usually airing Cantonese dramas local to us when I was around 13-15 years old. We watch all of these local dramas including those from Taiwan and Hong Kong just like our Chinese neighbors do.
Yue groups are actually consists of few tribal groups who descend down to South East Asian mainland from Southern China since Qin dynasty. These people are not identical to Han Chinese or simply the normal Chinese. The ancient name of Vietnam is 安南 Annam. Annam was actually a Chinese empire province and now it is represented by Northern Vietnam. They have many dynasties too like Chiew dynasty something and etc.
The inhabitant of central part of Vietnam were the Chams who were almost identical to Malays and Achehnese. They were Hindus and influenced by Indian civilization. They have their own city-states and their city-states were named according to Hindu religious epics. Other ethnic at the most southern part of Vietnam is the Khmer Khrom. They are the remnants of Funan ancient empire. Most of them are Buddhists but last time they were also Hindus like the Chams. The Chams today some of them were traditionalist Hindus especially in Vietnam and some of them in Cambodia are Muslim. I love Vietnamese style cuisine and their cuisine is almost identical to ours, hehe.
Thailand as a nation-state actually derive their country name from Tai-Kadai ethnic. Tai-Kadai ethnic is almost identical to Zhuang ethnic of Southern China. Thailand is a huge country and it actually could be divided into regional areas and provinces. The Northern part of Thailand is inhabited by people who are identical to Southern Chinese minority ethnics. The Southern part of Thailand is inhabited by Malays. The central part is of mixed population. The eastern part is populated by those who are identical to the Khmers in Cambodia and Laos. The Thais in Thailand eating sticky rice known as Khao Niao and they also use chopsticks just like Chinese but they are not Chinese. Their ancient dynasties are known as Sukhothai and at the northern part of Thailand the people also establish a kingdom as Lan Na or million rice field kingdom in contrast to their neighbor in China whose region is known as Sipsongpanna or 西雙版納 Shishuangbanna.
The Malays in Thailand are basically the same with the Malays in Kelantan state and Kedah state in Malaysia. They have their own city-states too before they were incorporated into Thailand through treaty and agreements with Siamese empire, British empire and with the ancient countries in our area at the Kra Isthmus. The pan-Thai spirit was first promoted by a Thai Chinese known as Plaek Phibul Songkram. I memorized all of the figures name because we have to answer history questions in Malaysian history syllabus about fellow ASEAN countries.
In South China if I am not mistaken there are also Dai ethnic. Some Thai people said, maybe China government trying to eliminate the spirit of Thai brotherhood so the character 泰 Tai was changed to 傣 Dai. I had watched few programs in Thai TV channel and yes Thai emperor still contacting these people and sending religious stuffs for them during festival and celebration just like what happened in our states in Malaysian peninsula northern part where Buddhists call it as baramee (blessings) of the emperor. Their language is identical and those who can speak in Thai could also understand the Southern Dai ethnic language.
In Southern Thailand such as Phuket island, there are also Baba Nyonya community who were actually the people of mixed ancestry between native and the Chinese. Their women wear kebaya and sarong like Malays in Malaysian southern states but they speak no Chinese. They only speak in Malay with smattering Chinese words of Fujianese or Teochew origin. They also pray to Chinese deities in Taoist temples. Now perhaps they also speak in Thai because it is their national language. But I am not surprised to see any Thai speaking in Chinese with me too. Last time I also helped a northern Thai lady who can't speak in Malay and English to go to immigration department in Komtar. We just talked with each other in Chinese though I can also speak in Thai because she choose to speak in Chinese rather than in Thai since she begin to talked with me in Chinese.
These people are well-known with their pickled fish in the jar maker. I used to tease Lao worker at my grandpa house by calling them par dak pakk menn (pickled fish stinky mouth), hahaha. It is not good actually teasing people. In Malay it is known as Ikan Pekasam. Their language is also identical to Thai language and those who speak in Thai language can understand their language. Both Thai language and Lao language are tonal language but Thai language has more complex system because it is a hybrid language. They also take sticky rice. I love Lao cooking too, the style of their cooking is the same with our home cooking style. I can't eat mamak food : (
This country in the north is populated by Burmese. Burmese are almost identical to the Tibetan but their school of Buddhism is different because Tibetan are Mahayana-Vajrayana Buddhists. Burmese are Theravada Buddhist just like Thais and other South East Asian mainland people who profess Buddhism as their religion. Burmese language is tonal just like Tibetan and Chinese. I also found a Myanmarese/Burmese lady working in Maju Jaya department store at Desa Universiti at our place here who speaks in Mandarin Chinese identical to Malaysian Chinese Mandarin. I think by passport she is not from China because she is a Myanmarese but maybe she is a Chinese whose identity were suppressed by her country.
There are also Yunnanese Chinese soldiers who fled to Myanmar during civil wars. Southern part of Myanmar is inhabited by Mon ethnic, sea people and also Malays who are identical to Malays in Kedah state. There are also Arab descent in southern Myanmar just like in Malaysian northern states and also in southern Thai region. Some of them are involved in the publishing of religious and prayer books for madrasah.
Many people from Vietnam, Laos, Myanmar and Thailand could also speak in Chinese dialect. They do not have to be specifically educated in Chinese or being a Chinese because they are close to the Sino-Sphere. My state of origin is a neighboring state to Thailand. I feel like crying when people looking weirdly at me when I speak in Chinese language. Last time nobody looking at me like that because in KL it is just a normal thing :'( I wish this brief post could also be an opener for more deeper knowledge about fellow ASEAN countries.
Sealed with prayers for mercy, peace and love, amin!