The Switch version will feature touchscreen and Joy-Con support.
Clannad is a romance visual novel developed by Key that first released for PC in April 2004. It has since been ported to various platforms, including PlayStation 2, PSP, Xbox 360, PlayStation 3, Android, and PlayStation 4. The PC and PlayStation 4 versions are the only two versions currently available officially in English. The PlayStation 4 version features both English and Japanese text in both its Japan and western editions, so it is possible the Switch version will feature the same.
Here is an overview of the game, via VNDB:
Okazaki Tomoya is a third year high school student at Hikarizaka Private High School, leading a life full of resentment. His mother passed away in a car accident when he was young, leading his father, Naoyuki, to resort to alcohol and gambling to cope. This resulted in constant fights between the two until Naoyuki dislocated Tomoya’s shoulder. Unable to play on his basketball team, Tomoya began to distance himself from other people. Ever since he has had a distant relationship with his father, naturally becoming a delinquent over time.
While on a walk to school, Tomoya meets a strange girl named Furukawa Nagisa, questioning if she likes the school at all. He finds himself helping her, and as time goes by, Tomoya finds his life heading towards a new direction.
Update 12/27/18 at 4:40 a.m.: Prototype has launched the teaser website for the Switch version of Clannad, confirming that it will feature both Japanese and English text.