倒: actually, on the contrary
副词 / adverbs
Tone colorsā tone 1á tone 2ǎ tone 3à tone 4a neutral
S + 倒 + V/Adj (contrary to expectation) | Adj 倒是 Adj，就是/可是…
The adverb 倒 (dào) signals a contrast with expectation or with what came before:
1. Surprise: 你倒说得轻松 ("easy for you to say!"), 没想到他倒先来了.
2. Concession: A 倒是 A，就是/可是 B = "it's A all right, but…": 这件衣服好看倒是好看，就是太贵了.
3. Urging: 你倒是说话呀！("well, say something!").
It's highly idiomatic and frequent in stories and dialogue.
Examples
这本小说长倒是长，可是一点儿也不无聊。
Zhè běn xiǎoshuō cháng dàoshì cháng, kěshì yìdiǎnr yě bù wúliáo.This novel is long, sure, but it's not boring at all.
我以为他会生气，他倒笑了。
Wǒ yǐwéi tā huì shēngqì, tā dào xiào le.I thought he'd get angry, but he actually laughed.
你说得倒容易，你来试试！
Nǐ shuō de dào róngyì, nǐ lái shìshi!Easy for you to say: you try it!
Common mistakes
✗ Confusing 倒 (dào, contrast adverb) with 倒 (dǎo, "to fall").
✗ 倒 before the subject: ✗ 倒他笑了 → ✓ 他倒笑了。