• 七色なないろ — seven colors / rainbow
• 第七だいなな — the seventh (ordinal)
• 七回ななかい — seven times
• 七夕たなばた — Tanabata (Star Festival)
• 七福神しちふくじん — Seven Lucky Gods

“七” is one of the earliest-learned number kanji. It’s simple to write with only two strokes, and you’ll see it everywhere from dates to festivals. It’s often read as しち, but in everyday speech, people may say なな to avoid confusion with いち (one).

私わたしのクラスに 七人しちにんの生徒せいとがいます。
There are seven students in my class.

七月しちがつはとても暑あついです。
July is very hot.