Not necessarily: you can choose to have several languages separated as different input methods (you can switch between them very quickly by sliding vertically from the space bar) OR you can go to "Settings / Languages" and select one of your active languages and inside its submenu add languages for multilingual typing. This way when you select that original language as input method it will use and recognise all the languages you added at once. I must say this can be tricky with glide typing, but still works pretty well.