

このお肉はちょっとかたいです。
かたいいすは好きじゃありません。
そのパン、かたい?
"かたい(硬い)" is in the lesson "Properties" (Level 26), along with 9 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.