On the one hand… on the other: 一方面……另一方面
复句 / complex sentences
Tone colorsā tone 1á tone 2ǎ tone 3à tone 4a neutral
一方面……另一方面…… presents two aspects of the same issue, or two complementary reasons: "on the one hand…, on the other…".
It's an argumentation pattern, great for explaining a decision or balancing a view. The second half often contains 也 or 又.
Unlike in English, it doesn't necessarily contrast: often the two aspects add up.
Examples
运动一方面可以锻炼身体，另一方面也可以交朋友。
Yùndòng yì fāngmiàn kěyǐ duànliàn shēntǐ, lìng yì fāngmiàn yě kěyǐ jiāo péngyou.Sport keeps you fit on the one hand, and helps you make friends on the other.
举办奥运会一方面很光荣，另一方面压力也很大。
Jǔbàn Àoyùnhuì yì fāngmiàn hěn guāngróng, lìng yì fāngmiàn yālì yě hěn dà.Hosting the Olympics is an honour, but also a lot of pressure.
我一方面想去看比赛，另一方面又没有时间。
Wǒ yì fāngmiàn xiǎng qù kàn bǐsài, lìng yì fāngmiàn yòu méiyǒu shíjiān.On the one hand I want to see the match; on the other, I don't have time.
Common mistakes
✗ 一方面……其他方面…… → ✓ 一方面……另一方面……
✗ 一边……另一边 → for simultaneous actions it's 一边……一边……, a different pattern.