

この辺りは流れが速いので、泳がないでください。
川の流れに気をつけてね。
今日は流れが強いので、遊泳禁止です。
"ながれ(流れ)" is in the lesson "Beach" (Level 17), along with 12 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.