Google has pushed voice search and actions to the forefront over the last few years, introducing features like the Google Now Launcher and the “OK Google” command. Many phones now let you initiate a search from any screen, and a few can even be woken up from slumber with the trigger phrase.
However, when you do a voice search, Google only listens for your one default language. If you speak multiple languages, you can change that in a few taps.
Head into the main Google app settings (open the Google app, or swipe over to the Google Now cards, then select Settings in the flyout menu on the left). From there, open the Voice section. The menu item you’re looking for is predictably called Languages. This will open up a new selection menu with dozens of languages, each one with a checkbox. You can select up to five of them for your phone to recognize on the fly, but make sure you long-press to pick a default language as well.
Selecting secondary languages allows you to switch back and forth with a limit of one language per search. Basically, Google detects the language you’re speaking for each search, then plugs in the right translation engine. If you have voice output enabled, the device will also speak in the detected language.
You won’t be able to mix and match words from multiple languages in the same query, but this is still much more convenient than going into the settings each time you want to use another tongue.