

子どもを怖がらせるような話はやめてください。
弟はお化けのまねをして、妹を怖がらせた。
そんなことを言って、怖がらせないでよ。
"こわがらせる(怖がらせる)" is in the lesson "Verbs 10" (Level 22), 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.