

小さな虫を殺すのはかわいそうだと思います。
この薬はばい菌を殺します。
その映画、最後に主人公が殺されるの?
"ころす(殺す)" is in the lesson "Verbs 11" (Level 23), along with 11 other useful words. LinDuo has 180 topic lessons like this one, 2,379 words in total. Every word has an illustration, a transcription and pronunciation in a female and a male voice. Just 10–15 minutes a day is enough to learn them all. Free, and works offline.