一点(儿)
yìdiǎn(r)
modifier
一下(儿)
yíxià(r)
verbal measure word

HSK2 TBCL2

Yìdiǎn(r) 一点(儿)/一點(兒) and yíxià(r) 一下(儿)/一下(兒) both express ‘a bit’ but they have distinct usages.

Yìdiǎn(r) 一点(儿)/一點(兒) is a modifier used with both nouns and adjectives, while yíxià(r) 一下(儿)/一下(兒) is a verbal measure word used with verbs describing actions.

Structure

Basic form

For basic structures check yìdiǎn(r) 一点(儿)/一點(兒) and yíxià(r) 一下(儿)/一下(兒).

Functions

1. Quantity vs. duration of action

Yìdiǎn(r) 一点(儿)/一點(兒) modifies nouns and indicates a small and indefinite quantity of something, while yíxià(r) 一下(儿)/一下(兒) modifies verbs and indicates a brief or quick action.

Yìdiǎn(r) 一点(儿)/一點(兒) is used before nouns to express ‘a little bit of something:

我学过一点(儿)中文。  
我學過一點(兒)中文。
Wǒ xué guo yìdiǎn(r) Zhōngwén.
I have learnt a bit of Chinese.
(Yìdiǎn(r) 一点(儿)/一點(兒) modifies the object ”Zhōngwén 中文”, indicating that the subject does not know much Chinese.)

Yíxià(r) 一下(儿)/一下(兒) is used after verbs to express that an action is brief:

我出去一下(儿)。
我出去一下(兒)。
Wǒ chūqu yíxià(r).
I'm going out for a bit.
(Yíxià(r) 一下(儿)/一下(兒) modifies the verb ”chūqu 出去“, indicating that the duration of the subject‘s leaving does not last long.)

2. Comparing vs. trying

Yìdiǎn(r) 一点(儿)/一點(兒) modifies adjectives and indicates a slight, vague difference, while yíxià(r) 一下(儿)/一下(兒) modifies verbs to suggest trying or attempting an action briefly.

Yìdiǎn(r) 一点(儿)/一點(兒) is used after adjectives to express that something is ‘a little bit more’ compared to something else. It might be a comparison between two things or an inherent comparison:

今天冷一点(儿)。
今天冷一點(兒)。
Jīntiān lěng yìdiǎn(r).
Today is a bit colder (compared to yesterday or some other time.)

Yíxià(r) 一下(儿)/一下(兒) is used after verbs to suggest ‘giving something a try’:

我试一下(儿)写这个字。
我試一下(兒)寫這個字。
Wǒ shì yíxià(r) xiě zhè ge zì.
Let me try writing this character.

Also check yíxià(r) 一下(儿)/一下(兒)

Also check yìdiǎn(r) 一点(儿)/一點(兒).