有点儿 / 一点儿【yǒudiǎnr / yìdiǎnr】

有点儿 and 一点儿 both mean "a bit", and where they sit decides which you need. 有点儿 goes before the adjective and says the speaker isn't happy about it.

一点儿 goes after the adjective and asks for an adjustment, or states a small difference.

Swapping them is the usual mistake.

• × 这个菜一点儿咸 → 这个菜有点儿咸
• × 请有点儿慢说 → 请说慢一点儿

有点儿 is short for yǒu yī diǎnr有一点儿, and both are correct. 有点 and 一点, without 儿, are the same words.

有点儿 is for things you'd rather were otherwise

贵, 累, 难, 咸, 远 take 有点儿 easily. A pleasant quality usually takes another adverb, such as tǐng挺 or hěn很. 有点儿 can also go before a verb of feeling or a negative.

一点儿 after an adjective is a comparison

慢一点儿 is slower than the current speed, 便宜一点儿 is cheaper than the price just quoted. That is why it works as a polite request.