

シートベルトを締めるのを忘れないで。
どうやってネクタイを締めるの?
ズボンが大きいから、ベルトを締めるよ。
"しめる(締める)" is in the lesson "Verbs 18" (Level 30), 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.