While many people believe that all the Chinese speak the same language, China in fact has not one language but several dozens. These are sometimes called “dialects”, but this word is misleading - they are usually mutually unintelligible, meaning that if two Chinese try speaking to each other using different dialects, chances are that they will not be able to understand each other. Each area in China typically has its own dialect which is the local language for that area. The language that we normally call “Chinese”, or more accurately “Mandarin“, is one of these local dialects - a slightly modified version of the dialect spoken in Beijing and its surroundings. Mandarin is the formal language in all of China and all classes in public schools are taught in this language, and as a result almost everyone in China can speak this dialect fluently (usually as a second language). Mandarin is by far the most widespread dialect and is the “common denominator” between Chinese of different provinces. The second-most common dialect is the dialect spoken in many areas of Guangdong (Canton) province, known as “Cantonese“. This dialect has managed to stay relatively “strong” in comparison to other local dialects, in my opinion largely due to two reasons:

1. Many of the overseas Chinese had originated from Guangdong province, and their dialect became common in Chinese communities outside of China.
2. Hong Kong, which had been until 1997 under British control, did not follow mainland China in its switch to Mandarin and kept Cantonese as their formal language (along with English). Hong Kong’s very-active film and music industry kept producing Cantonese-speaking films and songs, which were and still are popular in China.

In rural areas, usually the local dialect is king. In large cities the situation is a bit different - typically in the city outskirts people mostly speak the local dialect, while in the city center there is a larger concentration of Chinese who came from out of the province (and cannot speak the local dialect), so Mandarin will often be used for communication.

And this brings us to the language spoke in Shenzhen. First a quick review of the city’s history: Until 1979, Shenzhen was an unknown fishing village. In 1980 the Chinese government decided to make use of Shenzhen’s location next to the Hong Kong border and establish a Special Economic Zone. This resulted in Shenzhen developing very quickly until by 2007 it has become a thriving metropolis with a population of somewhere between 8-13 million  (depending on how you count).

This in-surge of population came from all over China, each person bringing his own dialect. Since every resident brought a different language with him, Mandarin had become the language of choice in Shenzhen - smack in the middle of Guangdong province, the stronghold of Cantonese. In this sense Shenzhen is unique, because even very thriving and diverse cities like Shanghai still tend to favor their local dialects.

However, that’s not the end of it. In the past few years ties between Hong Kong and Shenzhen have become tighter and tighter, with many people crossing back and forth between the cities - which are not at all far from each other. Shenzhen, although an expensive city in Chinese standards, is still cheap by Hong Kong standards. Suddenly people who work in Hong Kong (especially the outskirts closer to Shenzhen) realize - why rent an apartment in Hong Kong when they can get the same apartment for half the price in Shenzhen? And so, more and more Hong Kong residents move to Shenzhen and commute every day, across the border, to Hong Kong. This has two main effects - one, the influx of rich Hong-Kongians raises the prices in Shenzhen (especially real estate). Two, they bring with them their spoken language, which is Cantonese.

And thus a circle is closed - Shenzhen, a Cantonese-speaking village transformed into a Mandarin-speaking metropolin, is being pulled towards becoming a Cantonese-speaking suburb of Hong Kong. I believe that ties between Hong Kong and Shenzhen will only become tighter and tighter, and that the two cities will gradually combine into one entity. It remains to be seen who swallows whom, and what language they will speak…