Conversely / on the contrary (反之 / 与此相反)

Structure Claim A，反之 / 与此相反，claim B (opposite)

反之 (fǎnzhī) and 与此相反 (yǔ cǐ xiāngfǎn) introduce the case or situation OPPOSITE to the one just stated; they are contrast connectors of essay and press register. 反之 is the most concise and abstract — literally 'the reverse of this' — and often chains the opposite consequence (努力则有所得，反之则一无所获). 与此相反 ('in contrast to this') is more descriptive and usually opens a fresh clause painting the opposite picture. Unlike colloquial 相反 or all-purpose 但是, both belong to the cultivated written register.

Examples

努nǔ力lì则zé有yǒu所suǒ得dé，反fǎn之zhī则zé一yī无wú所suǒ获huò。
With effort one gains something; conversely, one gains nothing at all.
南nán方fāng多duō雨yǔ，与yǔ此cǐ相xiāng反fǎn，北běi方fāng十shí分fēn干gān燥zào。
It rains a lot in the south; conversely, the north is very dry.
理lǐ性xìng使shǐ人rén冷lěng静jìng，反fǎn之zhī，冲chōng动dòng往wǎng往wǎng误wù事shì。
Reason makes one calm; conversely, impulsiveness often ruins things.
有yǒu人rén视shì压yā力lì为wéi动dòng力lì，与yǔ此cǐ相xiāng反fǎn，也yě有yǒu人rén因yīn压yā力lì而ér崩bēng溃kuì。
Some see pressure as a driving force; on the contrary, others break down because of it.

Levels are indicative: they follow the standard Chinese Grammar Wiki (AllSet Learning) progression, not an official HSK 3.0 mapping. We never assign levels by eye.

This point and the other 370, with audio on every example, inside Wanyu.