

し月に日本へ行きます。
し月は桜がきれいですね。
いち、に、さん、し!もう一回。
"し(四)" is in the lesson "Numbers" (Level 3), along with 19 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.