>>40541duolingo doesnt always use words in the right context, or misses the nuance of asian languages. it also doesnt really make transitive vs intransitive verb usage and their accompanying particles very clear, which is an important thing in a lot of other languages, but not that important in english. i would say maybe use it as an aide to a textbook, but not as the main tool.
明かりを消す - (somebody) turns off a light
明かりが消げる - a light turns off
おもちゃを壊す - (somebody) breaks a toy
おもちゃが壊れる - a toy breaks
there is a different verb and particle to use if the verb is transitive vs intransitive. duolingo hardly teaches that matter other than just throwing a bunch of verbs at you and hoping you notice the difference.