

月に一回、母に電話します。
月にどのくらい本を読みますか。
月の終わりはいつも忙しいです。
"つき(月)" is in the lesson "Time 1" (Level 1), 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.