When you buy a bundled Switch package or buy game cards for the Switch, are the games in Chinese, English or both?
http://www.nintendolife.com/forums/nintendo-switch/supported_language_when_buying_physical_copies
It will vary from game to game. Most games should include an English option, except for Japanese exclusives. Checking the Japanese eShop page is the easiest way to find out which languages are supported. Many Japanese version games will include English on the cartridge in case of a wider Asian release (e.g. China, Singapore etc.), but may not include European languages. 日本語 (Nihingo) means Japanese language and 英語 (Eigo) means English language, so just keep that in mind should you check the Japanese eShop in future. Another way to check is to see if the English language eShop specifies Japanese as a supported language in any retail game. If not, then Japanese must be restricted to the Japanese release of the game (that may or may not include English on the cartridge).
Thanks