比 + difference: a bit, much, exact amount
句型 / sentence patterns (比字句)
Tone colorsā tone 1á tone 2ǎ tone 3à tone 4a neutral
A + 比 + B + Adj + 一点儿 / 得多 / 多了 / quantity
To specify how big the difference is, add something after the adjective:
一点儿 (a bit): 今天比昨天暖和一点儿.
得多 / 多了 (much): 这儿比那儿冷得多 / 冷多了.
Exact amount: 今天比昨天高五度 (5 degrees higher). 他比我大两岁 (he's two years older than me).
All of these come after the adjective, never before.
Examples
今天比昨天暖和一点儿。
Jīntiān bǐ zuótiān nuǎnhuo yìdiǎnr.Today is a bit warmer than yesterday.
哈尔滨比上海冷多了。
Hāěrbīn bǐ Shànghǎi lěng duō le.Harbin is much colder than Shanghai.
今天比昨天低八度。
Jīntiān bǐ zuótiān dī bā dù.Today is eight degrees lower than yesterday.
他比我大两岁。
Tā bǐ wǒ dà liǎng suì.He's two years older than me.
Common mistakes
✗ 今天比昨天一点儿冷 → ✓ 今天比昨天冷一点儿.
✗ 他比我两岁大 → ✓ 他比我大两岁.
✗ 今天比昨天有点儿冷 → ✓ 今天比昨天冷一点儿 (有点儿 doesn't go with 比).