China's top (and pretty much monopolist) taxi app, Didi Chuxing, is quietly trialing an English version.

The app, which doesn't even have an English listing in the App Store yet, started showing English translations to some users, according to Shanghai resident, Mathieu Bouchara.

Bouchara said that not only was his app's interface in English, Chinese addresses were also getting automatically translated.

However, this might be more trouble than it's worth for English-speaking users, he noted in an email.

Addresses were not spelled out in Chinese phonetics, but pretty much machine-translated for meaning, thereby becoming an entirely different word in English. That's likely to be confusing for some, who will suddenly be presented with English approximations of landmarks, rather than their Chinese names.

Bouchara said he was headed to "Tai Fu Ming Di Nan Men," but realised the Chinese characters were gone from the address. He wasn't shown the hanyu pinyin, or phonetics version either, but "Territory Shanghai China South Gate" -- a phrase that didn't make sense to him.

The app's help section was also translated to English, but parts of the app such as user credits remain in Chinese for now.

Didi's English version appears to be in closed trial. Several China-based users with phones set to English we spoke to said their apps were still in Chinese.

Didi's effort to translate to English likely helps fill the gap left behind by Uber, which all but exited the country last year after selling its Chinese business to Didi.

The U.S. taxi app couldn't handle the cost of competing with the massive Didi -- itself a merger of two huge warring taxi companies, when Kuaidi Dache and Didi Dache decided to stop fighting and become one in 2015.