

先生が来たら、みんな立つよ。
一日中立つ仕事は大変です。
どうしてそこに立つの?
"たつ(立つ)" is in the lesson "Verb antonyms" (Level 8), along with 15 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.