Correct

书到用时方恨少

/ shū dào yòng shí fāng hèn shǎo /
Strokes

Example

Definition

a is known in time of need

1
Shū
dào
yòng
shí
fāng
hèn
shǎo
  
,
shì
fēi
jīngguò
经过
zhī
不知
nán
  

Having a chance to use our book learning, we regret that it is meagre; having accomplished a task, we begin to appreciate its difficulty.