一点儿 vs 有点儿 — both mean "a bit", and they are not interchangeable

• 有点儿 + Adjective
  A bit too … — always a negative slant.
• Adjective + 一点儿
  A bit more … — neutral, usually a request or comparison.
• Verb + 一点儿 + Noun
  A little bit of something — a quantity.

Position tells them apart, and position also tells you the attitude. 有点儿 comes before the adjective and signals that the speaker is not happy: 这个有点儿贵。 (This is a bit pricey — I'd rather it weren't.)

一点儿 comes after the adjective and is emotionally flat. It is the everyday way to ask for an adjustment: 便宜一点儿，可以吗？ (A bit cheaper, could you?) 说慢一点儿。 (Speak a little slower.)

This is why 有点儿好 sounds strange: you do not complain about something being good. Positive adjectives normally take 有点儿 only when the speaker means it ironically or the quality is unwanted (有点儿甜 — a bit too sweet).

一点儿 has a second life as a plain quantity before a noun: 我想喝一点儿水。 (I'd like a little water.) In that use it does not compare anything. And in northern speech both often lose the 儿 in writing: 一点, 有点.

Want to hear these words in your own sentences? Paste any Chinese text into the Pinyin Annotator or the Chinese → Pinyin translator.

What is the difference between 一点儿 and 有点儿?

有点儿 goes before an adjective and implies the speaker is unhappy about it: 有点儿贵 (a bit too expensive). 一点儿 goes after the adjective and is neutral: 便宜一点儿 (a bit cheaper). Position and attitude go together.

Why is 有点儿好 wrong?

Because 有点儿 signals a complaint, and you do not complain about something being good. Use 很好 or 挺好的 instead. 有点儿 with a positive adjective only works when the quality is unwanted — 有点儿甜 (a bit too sweet).

How do you ask someone to speak more slowly in Chinese?

请说慢一点儿 (qǐng shuō màn yìdiǎnr). The adjective 慢 comes first and 一点儿 follows it, because this is a neutral request rather than a complaint.

Is it 一点儿 or 一点?

Both. The 儿 ending is standard in northern Mandarin and in most textbooks; southern speakers and much written Chinese drop it. 一点 and 有点 mean exactly the same as 一点儿 and 有点儿.