

掃除の前に、棚のほこりをおとすといいですよ。
年末に、エアコンのほこりをおとしました。
部屋に入る前に、服のほこりをおとしてね。
"ほこりをおとす(埃を落とす)" is in the lesson "Verbs 12" (Level 24), 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.