

写真の真ん中にいるのが姉です。
テーブルの真ん中に花を置きます。
真ん中の席は好きじゃないです。
"まんなか(真ん中)" is in the lesson "Adjectives 5" (Level 38), along with 10 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.