It's just for fun. Don't take it seriously.

只是为了好玩哈 不要太当真

We used to drive too fast, just for fun.

我们过去常常开得太快，就为了好玩。

I decided to learn Japanese just for fun.

我决定学日语只是为了好玩。

I decided to learn Spanish, just for fun.

我决定学习西班牙语，只是为了消遣。

I will take part in a voluntary labor instead of just for fun.

我将参加志愿劳动，而不是仅仅为了玩。

When kids participate in sport games just for fun, they will gain pleasure from the games, cultivate friendship with others and develop team spirit.

当孩子们为了娱乐而参与体育运动的时候，他们可以从中获得快乐，与他人建立友谊，并能树立良好的团队精神。