"He plays and she sings."
Translation:Li ludas kaj ŝi kantas.
Try the Canadian Multilingual Standard Keyboard Layout. It is easy to switch from the US international or other language to it and the ^ is to the right of our P on our QWERTY keyboard and can be applied to any letter! http://www.microsoft.com/resources/msdn/goglobal/keyboards/kbdcan.html
"lud" and "kant" are the roots for play and sing, but the infinitives are "ludi" and "kanti". If you want to say the verbs "play" and "sing", you would use their infinitives. However, the roots "lud" and "kant" are used in many other words, such as ludo (game) and kanto (song), so it is still smart to recognize that.
The ŝ is not a š. Look closely, the ^ faces the other way in Esperanto. If you can't type it that way Duolingo will accept sx, and outside of Duolingo using sh is pretty common (sh is the official alternate spelling according to LL Zamenhof, where "ŝ, ĥ, ĝ, ĵ, ŭ" become "sh, hh, gh, jh, u".