Correct

赶紧 vs 赶快

/ gǎnjǐn vs gǎnkuài /
Strokes

Definition

赶紧 and 赶快 both are Adverbs, which means [hastily; quickly].

Example

赶紧 and 赶快 both words means "to speed up an action", and both can be used in a declarative (foregone or future) sentence and an imperative sentence.
1
Zuótiān
昨天
shēng
发生
jiāotōng
交通
wài
意外
shí
  
,
men
他们
jīng
已经
xiàn
发现
chēzi
车子
yǒu
máobìng
毛病
  
,
xiǎng
gǎnjǐn
赶紧
  
(
gǎnkuài
赶快
  
)
shāchē
刹车
  
,
dànshì
但是
jīng
已经
láibu
来不及
le
  

There was no time left when they knew there was something wrong with their car. And therefore there was a traffic accident. (declarative, foregone)

2
Gǎnkuài
赶快
  
(
gǎnjǐn
赶紧
  
)
chū
出发
  
!
Shíjiān
时间
yào
wǎn
le
  
!

Please leave at once, or you'll be late. (imperative,future)

3
guǒ
如果
gǎnkuài
赶快
  
(
gǎnjǐn
赶紧
  
)
zǒu
  
,
jiù
gǎn
shàng
fēi
飞机
le
  

If you are not in a hurry, you'll miss the plane. (hypothetical, future)

4
Kuài
sòng
yuàn
医院
  
,
gǎnkuài
赶快
  
(
gǎnjǐn
赶紧
  
)
  
!

Take him to the hospital immediately. Hurry up, please.

Related

赶紧赶快