有点儿 vs 一点儿
副词 / adverbs
Tone colorsā tone 1á tone 2ǎ tone 3à tone 4a neutral
有点儿 + Adj / Adj + 一点儿
Both translate as "a little", but their position and nuance differ.
有点儿 + adjective (BEFORE the adjective): "a bit too", usually a complaint or something negative: 房租有点儿贵 (the rent is a bit expensive).
Adjective + 一点儿 (AFTER the adjective): used to compare or request: 便宜一点儿吧！(a bit cheaper, please!). 一点儿 can also follow a verb before a noun: 喝一点儿水.
Examples
这个房子有点儿小。
Zhège fángzi yǒudiǎnr xiǎo.This place is a bit small.
能便宜一点儿吗？
Néng piányi yìdiǎnr ma?Can you make it a bit cheaper?
我今天有点儿不舒服。
Wǒ jīntiān yǒudiǎnr bù shūfu.I'm feeling a bit unwell today.
请说慢一点儿。
Qǐng shuō màn yìdiǎnr.Please speak a bit more slowly.
Common mistakes
✗ 这个房间一点儿小 → ✓ 这个房间有点儿小.
✗ 请说有点儿慢 → ✓ 请说慢一点儿.
有点儿 + a positive adjective often sounds odd: 我有点儿高兴 is rare, prefer 我很高兴.