

この野菜は自然な甘さがあっておいしいです。
農薬を使わずに、自然な方法で野菜を作っています。
このりんごの赤い色は自然ですか。
"しぜんな(自然な)" is in the lesson "Farm" (Level 31), along with 13 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.