Correct

劲儿 vs 劲头儿

/ jìnr vs jìntóur /
Strokes

Definition

劲儿 and 劲头儿 both Nouns, which means “strength, energy”.

Example

劲儿 and 劲头儿 are interchangeable when mean "strength".
1
niánqīngzhuàng
年轻力壮
  
,
shǒushàng
手上
de
jìnr  
劲儿
  
(
jìntóur  
劲头儿
  
)
hěn
  

He is young and vigorous, and his hands have strength.

2
Zhè
tóu
niú
jìnr  
劲儿
  
(
jìntóur  
劲头儿
  
)
zhēn
  

The bull is really strong.

3
Tuō
拖拉机
de
jìnr  
劲儿
  
(
jìntóur  
劲头儿
  
)
bu
可不
xiǎo
  
,
néng
hǎoduō
好多
dōng
东西
ne
  

The tractor is so powerful that it pulls a lot of weight.

When functioning as the object of 用, 使, etc. usually 劲儿 is used.


4
yòng
jìnr  
劲儿
tuīkāi
推开
le
chénzhòng
沉重
de
mén
大门
  

He pushed the heavy gate with efforts.

5
Xiāngzi
箱子
hěn
chóng
  
,
tái
de
shíhou
时候
  
,
men
你们
liǎng
rén
de
shǐ
使
diǎnr  
点儿
jìnr  
劲儿
  
!

The box is very heavy, so you'd better exert some efforts to lift it up.

劲儿 is usually used to indicate sentiments, spirit, air, expression, etc.
Especially, in some set phrases, e.g. 冲劲儿 (vigor), 倔劲儿 (bluntness), 钻劲儿 (spirit of studying intensively), 傻劲儿 (folly, foolishness), etc.
6
yǒu
股子
jué
jìnr  
劲儿
  

He is a man of tenacity.

7
Qiáo
huài
jìnr  
劲儿
  
,
zǒngshì
总是
zhuōnòng
捉弄
rén
  

You are too tricky and always like playing tricks on others.

If 劲头儿 is used, there is usually a non-monosyllabic word in front.
eg, 倔强的劲头儿 (tenacity), 欢喜的劲头儿 (high spirits), 兴高采烈的劲头儿 (with joy and expedition), etc.
8
yǒu
zhǒng
chū
chéngguǒ
成果
xiū
罢休
dejìn
得劲
tóur  
头儿
  

She is determined to get good results.

劲头儿 can also mean "positive mood and interest", without an attributive.
9
men
他们
zuò
shìyàn
试验
hěn
yǒujìn
有劲
tóur  
头儿
  

They take great interests in doing experiment.

10
Shuō
xīng
歌星
lái
  
,
zhè
ge
rén
jìntóur  
劲头儿
shí
十足
  

When it comes to singers, they showed great interests in them.

劲儿 sometimes without an attributive can also mean "a positive sentiment" and often takes 上来.
上劲儿 or 来劲儿 has a similar usage.

11
Zài
lǐngdǎo
领导
de
biǎoyáng
表扬
鼓励
xià
  
,
xiǎowáng
小王
de
jìnr  
劲儿
  
(
jìntóur  
劲头儿
  
)
zhújiàn
逐渐
shànglái
上来
le
  

With the praise and encouragement of the leader, Xiao Wang's gradually cheered up.

12
Tīng
le
lǐngdǎo
领导
de
biǎoyáng
表扬
  
,
xiǎowáng
小王
gōngzuò
工作
de
gēng
shàng
jìnr  
劲儿
le
  

Xiao Wang worked harder than before at his leader's praise.

13
men
他们
yuè
gān
yuè
lái
jìnr  
劲儿
  
,
lián
chīfàn
吃饭
dōu
wàng
le
  

They become more and more interested in it and even forget their meals.